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Merge branch 'master' of ssh://gitea.fleyx.com:222/fanxb/demo-project

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fanxb 2024-03-23 20:51:07 +08:00
commit b1b713df35
48 changed files with 1674 additions and 18 deletions
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10
5.leetcode/src/com/fanxb/common/Q1.java
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@ -25,6 +25,16 @@ public class Q1 {
return null;
}
public int[] twoSum1(int[] nums, int target) {
Map<Integer, Integer> map = new HashMap<>();
for (int i = 0; i < nums.length; i++) map.put(nums[i], i);
for (int i = 0; i < nums.length; i++) {
Integer targetI = map.get(target - nums[i]);
if (targetI != null && targetI != i) return new int[]{i, map.get(target - nums[i])};
}
return null;
}
/**
* 更优，一次循环即可
*

26
5.leetcode/src/com/fanxb/common/Q11.java Normal file
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@ -0,0 +1,26 @@
package com.fanxb.common;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/10 10:49
*/
public class Q11 {
public int maxArea(int[] height) {
int length = height.length;
int max = 0, i = 0, j = length - 1;
while (i < j) {
int temp = (j - i) * Math.min(height[i], height[j]);
if (max < temp) max = temp;
if (height[i] > height[j]) j--;
else i++;
}
return max;
}
public static void main(String[] args) {
Q11 instance = new Q11();
}
}

68
5.leetcode/src/com/fanxb/common/Q12.java Normal file
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@ -0,0 +1,68 @@
package com.fanxb.common;
import java.util.HashMap;
import java.util.Map;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/10 10:49
*/
public class Q12 {
public String intToRoman(int num) {
StringBuilder stringBuilder = new StringBuilder();
while (num > 0) {
if (num >= 1000) {
stringBuilder.append("M");
num -= 1000;
} else if (num >= 900) {
stringBuilder.append("CM");
num -= 900;
} else if (num >= 500) {
stringBuilder.append("D");
num -= 500;
} else if (num >= 400) {
stringBuilder.append("CD");
num -= 400;
} else if (num >= 100) {
stringBuilder.append("C");
num -= 100;
} else if (num >= 90) {
stringBuilder.append("XC");
num -= 90;
} else if (num >= 50) {
stringBuilder.append("L");
num -= 50;
} else if (num >= 40) {
stringBuilder.append("XL");
num -= 40;
} else if (num >= 10) {
stringBuilder.append("X");
num -= 10;
} else if (num == 9) {
stringBuilder.append("IX");
num -= 9;
} else if (num >= 5) {
stringBuilder.append("V");
num -= 5;
} else if (num == 4) {
stringBuilder.append("IV");
num -= 4;
} else {
stringBuilder.append("I");
num -= 1;
}
}
return stringBuilder.toString();
}
public static void main(String[] args) {
Q12 instance = new Q12();
System.out.println(instance.intToRoman(3));
System.out.println(instance.intToRoman(9));
System.out.println(instance.intToRoman(58));
System.out.println(instance.intToRoman(1994));
}
}

38
5.leetcode/src/com/fanxb/common/Q125.java Normal file
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@ -0,0 +1,38 @@
package com.fanxb.common;
/**
* 题目地址： https://leetcode-cn.com/problems/partition-labels/
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q125 {
public boolean isPalindrome(String s) {
char[] chars = s.toLowerCase().toCharArray();
int i=0,j=chars.length-1;
while (i<j){
char ci = chars[i];
if(!isOk(ci)) {
i++;
continue;
}
char cj = chars[j];
if(!isOk(cj)){
j--;
continue;
}
if(ci !=cj) return false;
i++;j--;
}
return true;
}
private boolean isOk(char ci){
return (ci>='a' && ci<='z') || (ci>='0' && ci<='9');
}
public static void main(String[] args) {
int[] prices = {7, 1, 5, 3, 6, 4};
}
}

26
5.leetcode/src/com/fanxb/common/Q128.java Normal file
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@ -0,0 +1,26 @@
package com.fanxb.common;
import java.util.HashSet;
import java.util.Set;
public class Q128 {
public int longestConsecutive(int[] nums) {
Set<Integer> set = new HashSet<>(nums.length);
for (int num : nums) set.add(num);
int res = 0;
for (int num : nums) {
if (!set.contains(num - 1)) {
//说明num是一个序列的起点
int temp = num, curRes = 1;
while (set.contains(++temp)) curRes++;
res = Math.max(res, curRes);
}
}
return res;
}
public static void main(String[] args) {
}
}

45
5.leetcode/src/com/fanxb/common/Q13.java Normal file
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@ -0,0 +1,45 @@
package com.fanxb.common;
import java.util.HashMap;
import java.util.Map;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/10 10:49
*/
public class Q13 {
private static Map<Character, Integer> map = new HashMap<>(7);
static {
map.put('I', 1);
map.put('V', 5);
map.put('X', 10);
map.put('L', 50);
map.put('C', 100);
map.put('D', 500);
map.put('M', 1000);
}
public int romanToInt(String s) {
int res = 0;
char[] chars = s.toCharArray();
int length = chars.length;
for (int i = 0; i < length; i++) {
int cur = map.get(chars[i]), next = i == length - 1 ? 0 : map.get(chars[i + 1]);
if (cur < next) {
res += next - cur;
i++;
} else {
res += cur;
}
}
return res;
}
public static void main(String[] args) {
Q13 instance = new Q13();
System.out.println(instance.romanToInt("MCMXCIVI"));
}
}

39
5.leetcode/src/com/fanxb/common/Q134.java Normal file
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@ -0,0 +1,39 @@
package com.fanxb.common;
/**
* 分割回文串
*
* @author fanxb
* @date 2022/3/9 10:10
*/
public class Q134 {
public int canCompleteCircuit(int[] gas, int[] cost) {
int length = gas.length;
for (int i = 0; i < length; i++) {
gas[i] = gas[i] - cost[i];
}
for (int i = 0; i < length; i++) {
//try from i
int sum = 0;
boolean ok = true;
for (int j = 0; j < length; j++) {
sum += gas[(i + j) % length];
if (sum < 0) {
ok = false;
i += j;
break;
}
}
if (ok) {
return i;
}
}
return -1;
}
public static void main(String[] args) {
System.out.println(new Q134().canCompleteCircuit(new int[]{1, 2, 3, 4, 5}, new int[]{3, 4, 5, 1, 2}));
}
}

27
5.leetcode/src/com/fanxb/common/Q135.java
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@ -38,9 +38,32 @@ public class Q135 {
return count;
}
public static int candy1(int[] ratings) {
//every one set one candy
int length = ratings.length;
int[] res = new int[length];
Arrays.fill(res, 1);
for (int i = 1; i < length; i++) {
//从左到右遍历，如果下一个人分数更高那么多发一颗糖
if (ratings[i] > ratings[i - 1]) {
res[i] = res[i - 1] + 1;
}
}
for (int i = length - 2; i >= 0; i--) {
if (ratings[i] > ratings[i + 1] && res[i] <= res[i + 1]) {
res[i] = res[i + 1] + 1;
}
}
int sum = 0;
for (int temp : res) {
sum += temp;
}
return sum;
}
public static void main(String[] args) {
int[] s = {1, 2, 87, 87, 87, 2, 1};
int[] s = {1, 3, 4, 5, 2};
System.out.println(Arrays.toString(s));
System.out.println(candy(s));
System.out.println(candy1(s));
}
}

17
5.leetcode/src/com/fanxb/common/Q138.java
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@ -43,4 +43,21 @@ public class Q138 {
}
return res.next;
}
public Node newCopy(Node head) {
Map<Node, Node> map = new HashMap<>();
Node cur = head;
while (cur != null) {
map.put(cur, new Node(cur.val));
cur = cur.next;
}
cur = head;
while (cur != null) {
Node n = map.get(cur);
n.random = map.get(cur.random);
n.next = map.get(cur.next);
cur = cur.next;
}
return map.get(head);
}
}

47
5.leetcode/src/com/fanxb/common/Q14.java Normal file
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@ -0,0 +1,47 @@
package com.fanxb.common;
import java.util.HashMap;
import java.util.Map;
import java.util.stream.Stream;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/10 10:49
*/
public class Q14 {
public String longestCommonPrefix(String[] strs) {
if (strs.length == 1) return strs[0];
StringBuilder res = new StringBuilder();
int length = strs.length;
int minLength = Stream.of(strs).map(String::length).min(Integer::compare).orElse(0);
char a, b, c;
for (int i = 0; i < minLength; i++) {
for (int j = 1; j < length; j++) {
if (strs[j].charAt(i) != strs[j - 1].charAt(i)) return res.toString();
}
res.append(strs[0].charAt(i));
}
return res.toString();
}
public String longestCommonPrefix1(String[] strs) {
if (strs.length == 1) return strs[0];
String res = strs[0];
for (int i = 1; i < strs.length; i++) {
StringBuilder temp = new StringBuilder();
for (int j = 0; j < Math.min(res.length(), strs[i].length()); j++) {
if (res.charAt(j) == strs[i].charAt(j)) temp.append(res.charAt(j));
else break;
}
if (temp.length() == 0) return "";
res = temp.toString();
}
return res;
}
public static void main(String[] args) {
Q14 instance = new Q14();
}
}

33
5.leetcode/src/com/fanxb/common/Q141.java Normal file
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@ -0,0 +1,33 @@
package com.fanxb.common;
import java.util.HashMap;
import java.util.Map;
/**
* TODO
*
* @author FleyX
* @date 2022/3/3 22:35
*/
public class Q141 {
private static class Node {
int val;
Node next;
public Node(int val) {
this.val = val;
this.next = null;
}
}
public boolean hasCycle(ListNode head) {
if (head == null || head.next == null) return false;
ListNode fast = head, slow = head;
while (fast.next != null && fast.next.next != null) {
fast = fast.next.next;
slow = slow.next;
if (fast == slow) return true;
}
return false;
}
}

42
5.leetcode/src/com/fanxb/common/Q15.java Normal file
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@ -0,0 +1,42 @@
package com.fanxb.common;
import java.util.*;
import java.util.stream.Stream;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/10 10:49
*/
public class Q15 {
public List<List<Integer>> threeSum(int[] nums) {
Arrays.sort(nums);
List<List<Integer>> res = new ArrayList<>();
Set<String> has = new HashSet<>();
int length = nums.length;
for (int i = 0; i < length - 2; i++) {
if (nums[i] > 0) {
return res;
}
int l = i + 1, r = length - 1;
while (l < r) {
int sum = nums[i] + nums[l] + nums[r];
if (sum == 0) {
String key = nums[i] + "," + nums[l] + "," + nums[r];
if (!has.contains(key)) {
res.add(new ArrayList<>(Arrays.asList(nums[i], nums[l], nums[r])));
has.add(key);
}
break;
} else if (sum > 0) r--;
else l++;
}
}
return res;
}
public static void main(String[] args) {
Q15 instance = new Q15();
}
}

64
5.leetcode/src/com/fanxb/common/Q150.java Normal file
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@ -0,0 +1,64 @@
package com.fanxb.common;
import java.util.Stack;
public class Q150 {
public void gameOfLife(int[][] board) {
int m = board.length, n = board[0].length;
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
int aliveCount = 0;
if (i > 0 && j > 0 && board[i - 1][j - 1] >= 1) aliveCount++;
if (i > 0 && board[i - 1][j] >= 1) aliveCount++;
if (i > 0 && j < n - 1 && board[i - 1][j + 1] >= 1) aliveCount++;
if (j > 0 && board[i][j - 1] >= 1) aliveCount++;
if (j < m - 1 && board[i][j + 1] >= 1) aliveCount++;
if (i < m - 1 && j > 0 && board[i + 1][j - 1] >= 1) aliveCount++;
if (i < m - 1 && board[i + 1][j] >= 1) aliveCount++;
if (i < m - 1 && j < n - 1 && board[i + 1][j + 1] >= 1) aliveCount++;
if (board[i][j] == 0) {
//死到活 -1
if (aliveCount == 3) board[i][j] = -1;
} else {
//活到死 2
if (aliveCount < 2 || aliveCount > 3) board[i][j] = 2;
}
}
}
for (int i = 0; i < m; i++) {
for (int j = 0; j < n; j++) {
if (board[i][j] == -1) board[i][j] = 1;
else if (board[i][j] == 2) board[i][j] = 0;
}
}
}
public int evalRPN(String[] tokens) {
Stack<Integer> stack = new Stack<>();
for (String str : tokens) {
switch (str) {
case "+":
stack.push(stack.pop() + stack.pop());
break;
case "-":
stack.push(-stack.pop() + stack.pop());
break;
case "*":
stack.push(stack.pop() * stack.pop());
break;
case "/":
int num1 = stack.pop(), num2 = stack.pop();
stack.push(num2 / num1);
break;
default:
stack.push(Integer.valueOf(str));
}
}
return stack.pop();
}
public static void main(String[] args) {
}
}

28
5.leetcode/src/com/fanxb/common/Q151.java Normal file
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@ -0,0 +1,28 @@
package com.fanxb.common;
import java.util.Stack;
public class Q151 {
public String reverseWords(String s) {
Stack<String> stack = new Stack<>();
StringBuilder temp = new StringBuilder();
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == ' ') {
if (temp.length() > 0) {
stack.push(temp.toString());
temp = new StringBuilder();
}
} else {
temp.append(s.charAt(i));
}
}
if (temp.length() > 0) stack.push(temp.toString());
StringBuilder res = new StringBuilder();
res.append(stack.pop());
while (!stack.isEmpty()) res.append(" ").append(stack.pop());
return res.toString();
}
public static void main(String[] args) {
}
}

28
5.leetcode/src/com/fanxb/common/Q155.java Normal file
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@ -0,0 +1,28 @@
package com.fanxb.common;
import java.util.LinkedList;
public class Q155 {
private LinkedList<Integer[]> stack = new LinkedList<>();
public Q155() {
}
public void push(int val) {
int min = stack.isEmpty() ? val : Math.min(stack.getFirst()[1], val);
stack.push(new Integer[]{val, min});
}
public void pop() {
stack.removeFirst();
}
public int top() {
return stack.getFirst()[0];
}
public int getMin() {
return stack.getFirst()[1];
}
}

13
5.leetcode/src/com/fanxb/common/Q167.java
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@ -1,6 +1,7 @@
package com.fanxb.common;
import java.util.Arrays;
import java.util.EnumSet;
/**
* 两数之和 II - 输入有序数组
@ -25,9 +26,19 @@ public class Q167 {
i++;
}
}
return new int[]{i+1, j+1};
return new int[]{i + 1, j + 1};
}
public int[] twoSum(int[] numbers, int target) {
int i = 0, j = numbers.length - 1;
while (i < j) {
int sum = numbers[i] + numbers[j];
if (sum == target) return new int[]{i+1, j+1};
else if (sum > target) j--;
else j++;
}
return null;
}
public static void main(String[] args) {
int[] numbers = {2, 7, 11, 15};

44
5.leetcode/src/com/fanxb/common/Q2.java
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@ -62,17 +62,39 @@ public class Q2 {
return res;
}
public ListNode addTwoNumbers1(ListNode l1, ListNode l2) {
ListNode res = new ListNode(0);
ListNode temp = null;
//是否进位
boolean jw = false;
while (l1 != null || l2 != null) {
if (temp == null) temp = res;
else {
temp.next = new ListNode(0);
temp = temp.next;
}
if (l1 != null) {
temp.val += l1.val;
l1 = l1.next;
}
if (l2 != null) {
temp.val += l2.val;
l2 = l2.next;
}
if (jw) {
temp.val += 1;
jw = false;
}
if (temp.val >= 10) {
jw = true;
temp.val -= 10;
}
}
if (jw) temp.next = new ListNode(1);
return res;
}
public static void main(String[] args) {
ListNode l1 = new ListNode(2);
l1.next = new ListNode(4);
l1.next.next = new ListNode(9);
ListNode l2 = new ListNode(5);
l2.next = new ListNode(6);
l2.next.next = new ListNode(4);
l2.next.next.next = new ListNode(9);
new Q2().addTwoNumbers(l1, l2);
// new Q2().addTwoNumbers(new ListNode(0), new ListNode(0));
}
}

25
5.leetcode/src/com/fanxb/common/Q202.java Normal file
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@ -0,0 +1,25 @@
package com.fanxb.common;
import java.util.HashSet;
import java.util.Set;
public class Q202 {
public boolean isHappy(int n) {
Set<Long> cache = new HashSet<>();
long temp = n;
while (true) {
String[] strs = Long.toString(temp).split("");
long res = 0;
for (String s : strs) res += (long) Integer.parseInt(s) * Integer.parseInt(s);
if (res == 1) return true;
if (cache.contains(res)) return false;
cache.add(res);
temp = res;
}
}
public static void main(String[] args) {
new Q202().isHappy(2);
}
}

22
5.leetcode/src/com/fanxb/common/Q205.java Normal file
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@ -0,0 +1,22 @@
package com.fanxb.common;
import java.util.Arrays;
public class Q205 {
public boolean isIsomorphic(String s, String t) {
int[] map = new int[128];
Arrays.fill(map, -1);
int length = s.length();
for (int i = 0; i < length; i++) {
char tc = t.charAt(i), sc = s.charAt(i);
if (map[tc] == -1) map[tc] = sc;
if (map[tc] != sc) return false;
}
return true;
}
public static void main(String[] args) {
int[] s = {1, 2, 3, 1};
}
}

27
5.leetcode/src/com/fanxb/common/Q209.java Normal file
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@ -0,0 +1,27 @@
package com.fanxb.common;
import java.util.Arrays;
public class Q209 {
public int minSubArrayLen(int target, int[] nums) {
int res = Integer.MAX_VALUE, l = 0, r = 0;
int sum = 0;
while (r < nums.length) {
//循环添加右边的元素到窗口中
sum += nums[r];
//如果和大于target了，就开始减掉左边的元素，并计算最小值
while (sum >= target) {
res = Math.min(res, r - l + 1);
sum -= nums[l];
l++;
}
r++;
}
return res == Integer.MAX_VALUE ? 0 : res;
}
public static void main(String[] args) {
int[] s = {1, 2, 3, 1};
}
}

30
5.leetcode/src/com/fanxb/common/Q21.java Normal file
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@ -0,0 +1,30 @@
package com.fanxb.common;
public class Q21 {
public ListNode mergeTwoLists(ListNode list1, ListNode list2) {
if (list2 == null) return list1;
if (list1 == null) return list2;
ListNode res = null;
if (list1.val < list2.val) {
res = list1;
list1 = list1.next;
} else {
res = list2;
list2 = list2.next;
}
ListNode temp = res;
while (list1 != null && list2 != null) {
if (list1.val < list2.val) {
temp.next = list1;
list1 = list1.next;
} else {
temp.next = list2;
list2 = list2.next;
}
temp = temp.next;
}
if (list1 != null) temp.next = list1;
else temp.next = list2;
return res;
}
}

20
5.leetcode/src/com/fanxb/common/Q219.java Normal file
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@ -0,0 +1,20 @@
package com.fanxb.common;
import java.util.*;
public class Q219 {
public boolean containsNearbyDuplicate(int[] nums, int k) {
Map<Integer, Integer> map = new HashMap<>();
for (int i = 0; i < nums.length; i++) {
int num = nums[i];
Integer index = map.get(num);
if (index != null && Math.abs(i - index) <= k) return true;
map.put(num, i);
}
return false;
}
public static void main(String[] args) {
}
}

72
5.leetcode/src/com/fanxb/common/Q224.java Normal file
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@ -0,0 +1,72 @@
package com.fanxb.common;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
public class Q224 {
public int calculate(String s) {
Stack<String> stack = new Stack<>();
int len = s.length();
for (int i = 0; i < len; i++) {
char ch = s.charAt(i);
switch (ch) {
case ' ':
break;
case '(':
case '+':
case '-':
stack.push(ch + "");
break;
case ')':
List<String> strs = new ArrayList<>();
String temp;
while (!(temp = stack.pop()).equals("("))
strs.add(temp);
stack.push(cal(strs).toString());
break;
default:
//找到数字
StringBuilder builder = new StringBuilder().append(ch);
for (i = i + 1; i < len; i++) {
char ca = s.charAt(i);
if (ca >= '0' && ca <= '9') builder.append(ca);
else break;
}
i--;
stack.push(builder.toString());
}
}
List<String> strings = new ArrayList<>();
while (!stack.isEmpty())
strings.add(stack.pop());
return cal(strings);
}
private Integer cal(List<String> strs) {
int len = strs.size();
if (len == 1) return Integer.valueOf(strs.get(0));
if (len == 2) return Integer.valueOf(strs.get(1) + strs.get(0));
String first = strs.get(len - 1);
int i, num1;
if (first.equals("-")) {
num1 = -1 * Integer.parseInt(strs.get(len - 2));
i = len - 3;
} else {
num1 = Integer.parseInt(first);
i = len - 2;
}
for (; i >= 0; i -= 2) {
if (strs.get(i).equals("+")) {
num1 += Integer.parseInt(strs.get(i - 1));
} else {
num1 -= Integer.parseInt(strs.get(i - 1));
}
}
return num1;
}
public static void main(String[] args) {
System.out.println(new Q224().calculate("-2+1"));
}
}

20
5.leetcode/src/com/fanxb/common/Q228.java Normal file
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@ -0,0 +1,20 @@
package com.fanxb.common;
import java.util.LinkedList;
import java.util.List;
public class Q228 {
public List<String> summaryRanges(int[] nums) {
List<String> res = new LinkedList<>();
if (nums.length == 0) return res;
int startIndex = 0, length = nums.length;
for (int i = 1; i < length; i++) {
if (nums[i] - nums[startIndex] != i - startIndex) {
res.add(startIndex == i - 1 ? String.valueOf(nums[startIndex]) : (nums[startIndex] + "->" + nums[i - 1]));
startIndex = i;
}
}
res.add(startIndex == length - 1 ? String.valueOf(nums[startIndex]) : (nums[startIndex] + "->" + nums[length - 1]));
return res;
}
}

33
5.leetcode/src/com/fanxb/common/Q238.java Normal file
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@ -0,0 +1,33 @@
package com.fanxb.common;
import java.util.Arrays;
import java.util.LinkedList;
public class Q238 {
public int[] productExceptSelf(int[] nums) {
int length = nums.length;
if (length <= 1) return nums;
int[] left = new int[length];
left[0] = nums[0];
for (int i = 1; i < length; i++) {
left[i] = left[i - 1] * nums[i];
}
int[] right = new int[length];
right[length - 1] = nums[length - 1];
for (int i = length - 2; i >= 0; i--) {
right[i] = right[i + 1] * nums[i];
}
for (int i = 1; i < length - 1; i++) {
nums[i] = left[i - 1] * right[i + 1];
}
nums[0] = right[1];
nums[length - 1] = left[length - 2];
return nums;
}
public static void main(String[] args) {
System.out.println(Arrays.toString(new Q238().productExceptSelf(new int[]{1, 0})));
}
}

24
5.leetcode/src/com/fanxb/common/Q242.java Normal file
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@ -0,0 +1,24 @@
package com.fanxb.common;
/**
* @author fanxb
* @date 2021-10-25-下午4:25
*/
public class Q242 {
public boolean isAnagram(String s, String t) {
int sn = s.length(), tn = t.length();
if (sn != tn) return false;
int[] count = new int[128];
for (int i = 0; i < sn; i++) {
count[s.charAt(i)]++;
count[t.charAt(i)]--;
}
for (int j : count) if (j != 0) return false;
return true;
}
public static void main(String[] args) {
int[][] params = {{-1, 3}};
}
}

72
5.leetcode/src/com/fanxb/common/Q25.java
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@ -45,12 +45,82 @@ public class Q25 {
}
}
public ListNode newReverseKGroup(ListNode head, int k) {
if (k == 1) return head;
boolean firstDeal = true;
int count = 0;
ListNode res = head, left = null, right, lastRight = null;
while (head != null) {
if (left == null) left = head;
count++;
if (count == k) {
right = head;
reverse(left, right);
if (firstDeal) {
res = right;
firstDeal = false;
} else {
lastRight.next = right;
}
lastRight = left;
head = left.next;
left = null;
count = 0;
} else {
head = head.next;
}
}
return res;
}
private void reverse(ListNode start, ListNode end) {
ListNode last = start, current = start.next, next, temp = end.next;
while (current != null && current != temp) {
next = current.next;
current.next = last;
last = current;
current = next;
}
start.next = temp;
}
public ListNode new1ReverseKGroup(ListNode head, int k) {
ListNode res = new ListNode(0);
res.next = head;
ListNode pre = res, next;
while (head != null) {
ListNode end = head;
for (int i = 0; i < k - 1 && end != null; i++) end = end.next;
if (end == null) break;
next = end.next;
end.next = null;
pre.next = end;
reverse1(head);
head.next = next;
pre = head;
head = head.next;
}
return res.next;
}
public ListNode reverse1(ListNode head) {
ListNode pre = head, cur = head.next, next;
while (cur != null) {
next = cur.next;
cur.next = pre;
pre = cur;
cur = next;
}
return pre;
}
public static void main(String[] args) {
ListNode node = new ListNode(1);
node.next = new ListNode(2);
node.next.next = new ListNode(3);
node.next.next.next = new ListNode(4);
node.next.next.next.next = new ListNode(5);
new Q25().reverseKGroup(node, 3);
new Q25().new1ReverseKGroup(node, 2);
}
}

28
5.leetcode/src/com/fanxb/common/Q274.java Normal file
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@ -0,0 +1,28 @@
package com.fanxb.common;
import java.util.Arrays;
import java.util.Collections;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/11 9:56
*/
public class Q274 {
public int hIndex(int[] citations) {
Arrays.sort(citations);
int length = citations.length, count = 0;
for (int i = length - 1; i >= 0; i--) {
if (citations[i] < count + 1) {
break;
}
count++;
}
return count;
}
public static void main(String[] args) {
System.out.println(new Q274().hIndex(new int[]{1, 3, 1}));
}
}

33
5.leetcode/src/com/fanxb/common/Q290.java Normal file
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@ -0,0 +1,33 @@
package com.fanxb.common;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/11 9:56
*/
public class Q290 {
public boolean wordPattern(String pattern, String s) {
List<String> arr = Stream.of(s.split(" ")).filter(item -> !item.isEmpty()).collect(Collectors.toList());
if (arr.size() != pattern.length()) return false;
String[] map = new String[128];
Map<String, Character> map1 = new HashMap<>(arr.size());
for (int i = 0; i < pattern.length(); i++) {
char c = pattern.charAt(i);
String str = arr.get(i);
if (map[c] == null) map[c] = str;
map1.putIfAbsent(str, c);
if (!map[c].equals(str) || !map1.get(str).equals(c)) return false;
}
return true;
}
public static void main(String[] args) {
}
}

27
5.leetcode/src/com/fanxb/common/Q3.java
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@ -39,7 +39,32 @@ public class Q3 {
return Math.max(characters.size(), res);
}
public int lengthOfLongestSubstring1(String s) {
int l = 0, r = 0, length = s.length();
int[] map = new int[129];
int res = 0;
while (r < length) {
char c = s.charAt(r);
boolean has = map[c] == 1;
if (has) {
res = Math.max(res, r - l);
//遇到重复的，把l右移直到排除掉重复的
while (true) {
char c1 = s.charAt(l);
map[c1] = 0;
l++;
if (c1 == c) break;
}
} else if (r == length - 1) {
res = Math.max(res, r - l + 1);
}
map[c] = 1;
r++;
}
return res;
}
public static void main(String[] args) {
System.out.println(new Q3().lengthOfLongestSubstring("bbbbbbbbbbbbbbbbb"));
System.out.println(new Q3().lengthOfLongestSubstring1("abcabcbb"));
}
}

56
5.leetcode/src/com/fanxb/common/Q36.java Normal file
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@ -0,0 +1,56 @@
package com.fanxb.common;
import java.util.Arrays;
/**
*
*/
public class Q36 {
public boolean isValidSudoku(char[][] board) {
boolean[] check = new boolean[10];
char c;
for (int i = 0; i < 9; i++) {
//检查行
for (int j = 0; j < 9; j++) {
c = board[i][j];
if (c != '.') {
int num = c - '0';
if (check[num]) return false;
check[num] = true;
}
}
Arrays.fill(check, false);
//检查列
for (int j = 0; j < 9; j++) {
c = board[j][i];
if (c != '.') {
int num = c - '0';
if (check[num]) return false;
check[num] = true;
}
}
Arrays.fill(check, false);
//检查小9宫格
int starti = 3 * (i / 3), startj = (i % 3) * 3;
for (int x = 0; x < 3; x++) {
for (int y = 0; y < 3; y++) {
c = board[starti + x][startj + y];
if (c != '.') {
int num = c - '0';
if (check[num]) return false;
check[num] = true;
}
}
}
Arrays.fill(check, false);
}
return true;
}
public static void main(String[] args) {
char[][] chars =
new char[][]{{'5', '3', '.', '.', '7', '.', '.', '.', '.'}, {'6', '.', '.', '1', '9', '5', '.', '.', '.'}, {'.', '9', '8', '.', '.', '.', '.', '6', '.'}, {'8', '.', '.', '.', '6', '.', '.', '.', '3'}, {'4', '.', '.', '8', '.', '3', '.', '.', '1'}, {'7', '.', '.', '.', '2', '.', '.', '.', '6'}, {'.', '6', '.', '.', '.', '.', '2', '8', '.'}, {'.', '.', '.', '4', '1', '9', '.', '.', '5'}, {'.', '.', '.', '.', '8', '.', '.', '7', '9'}};
System.out.println(new Q36().isValidSudoku(chars));
}
}

26
5.leetcode/src/com/fanxb/common/Q383.java Normal file
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@ -0,0 +1,26 @@
package com.fanxb.common;
/**
* 两数相加
*
* @author fanxb
* @date 2021/6/1
**/
public class Q383 {
public boolean canConstruct(String ransomNote, String magazine) {
int[] charCount = new int[128];
for (int i = 0; i < magazine.length(); i++) {
charCount[magazine.charAt(i)]++;
}
for (int i = 0; i < ransomNote.length(); i++) {
char c = ransomNote.charAt(i);
if (charCount[c] == 0)
return false;
charCount[c]--;
}
return true;
}
public static void main(String[] args) {
}
}

35
5.leetcode/src/com/fanxb/common/Q392.java Normal file
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@ -0,0 +1,35 @@
package com.fanxb.common;
/**
* 两数相加
*
* @author fanxb
* @date 2021/6/1
**/
public class Q392 {
public boolean isSubsequence(String s, String t) {
int sLength=s.length(),tLength=t.length(),si=0,ti=0;
while (si<sLength && ti<tLength){
if(t.charAt(ti) == s.charAt(si)){
si++;ti++;
continue;
}
int i=ti+1;
for(;i<tLength;i++){
if(t.charAt(i)==s.charAt(si)){
ti = i+1;
si++;
break;
}
}
if(i==tLength){
si=0;
ti++;
}
}
return si>=sLength;
}
public static void main(String[] args) {
}
}

1
5.leetcode/src/com/fanxb/common/Q401.java
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@ -1,6 +1,5 @@
package com.fanxb.common;
import com.sun.tools.jconsole.JConsoleContext;
import java.util.*;

22
5.leetcode/src/com/fanxb/common/Q42.java
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@ -67,9 +67,31 @@ public class Q42 {
return res;
}
public int trap2(int[] height) {
int length = height.length;
//i左边的最大高度
int[] left = new int[length];
left[0] = 0;
//i右边的最大高度
int[] right = new int[length];
right[length - 1] = 0;
for (int i = 1; i < length; i++) {
left[i] = Math.max(left[i - 1], height[i - 1]);
right[length - i - 1] = Math.max(right[length - i], height[length - i]);
}
int res = 0;
for (int i = 1; i < length - 1; i++) {
int temp = Math.min(left[i], right[i]) - height[i];
if (temp > 0) {
res += temp;
}
}
return res;
}
public static void main(String[] args) {
System.out.println(new Q42().trap(new int[]{0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1}));
System.out.println(new Q42().trap1(new int[]{0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1}));
System.out.println(new Q42().trap2(new int[]{0, 1, 0, 2, 1, 0, 1, 3, 2, 1, 2, 1}));
}
}

49
5.leetcode/src/com/fanxb/common/Q45.java Normal file
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@ -0,0 +1,49 @@
package com.fanxb.common;
import java.util.Stack;
/**
* @author fanxb
* @date 2021-11-03-下午3:12
*/
public class Q45 {
public int jump(int[] nums) {
int maxIndex = 0;//下一跳能到达的最远边界
int end = 0; //一次跳跃的边界
int step = 0;//使用的部署
//只需走到倒数第二个节点即可
for (int i = 0; i < nums.length-1; i++) {
//look for next step's max value
maxIndex = Math.max(maxIndex, i+nums[i]);
//走到一步的边界了，已经找到下一跳的起点
if(i==end){
step++;
end = maxIndex;
}
}
return step;
}
public int solve(int[] nums,int i,int[] map){
if(i>nums.length-1) return 0;
if(map[i]>0) return map[i];
int minStep = 100000,step;
int v = nums[i];
for(int j=0;j<v;j++){
step = solve(nums,i+j+1,map);
minStep = Math.min(minStep,step+1);
}
map[i] = minStep;
return minStep;
}
public int jump1(int[] nums){
int[] map = new int[nums.length];
return solve(nums,0,map);
}
public static void main(String[] args) {
}
}

35
5.leetcode/src/com/fanxb/common/Q48.java Normal file
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@ -0,0 +1,35 @@
package com.fanxb.common;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Stack;
public class Q48 {
public void rotate(int[][] matrix) {
int length = matrix.length;
for (int i = 0; i < length / 2; i++) {
int length1 = length - i * 2;
for (int j = 0; j < length1-1; j++) {
int temp = matrix[i + j][i + length1 - 1];
matrix[i + j][i + length1 - 1] = matrix[i][i + j];
int temp1 = matrix[i + length1 - 1][i + length1 - 1 - j];
matrix[i + length1 - 1][i + length1 - 1 - j] = temp;
temp = matrix[i+length1-1-j][i];
matrix[i+length1-1-j][i] = temp1;
matrix[i][i + j] = temp;
}
}
}
public static void main(String[] args) {
int[][] arr = new int[][]{{5,1,9,11},{2,4,8,10},{13,3,6,7},{15,14,12,16}};
Q48 ins = new Q48();
ins.rotate(arr);
for (int[] temp : arr) {
System.out.println(Arrays.toString(temp));
}
}
}

25
5.leetcode/src/com/fanxb/common/Q49.java Normal file
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@ -0,0 +1,25 @@
package com.fanxb.common;
import java.util.*;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q49 {
public List<List<String>> groupAnagrams(String[] strs) {
Map<String, List<String>> map = new HashMap<>();
for (String str : strs) {
char[] chars = str.toCharArray();
Arrays.sort(chars);
map.computeIfAbsent(new String(chars), k -> new LinkedList<>()).add(str);
}
return new ArrayList<>(map.values());
}
public static void main(String[] args) {
}
}

61
5.leetcode/src/com/fanxb/common/Q54.java Normal file
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@ -0,0 +1,61 @@
package com.fanxb.common;
import java.util.LinkedList;
import java.util.List;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q54 {
public List<Integer> spiralOrder(int[][] matrix) {
List<Integer> list = new LinkedList<>();
list.add(matrix[0][0]);
int i = 0, j = 0, count = 1, m = matrix.length, n = matrix[0].length;
int type = 0;
matrix[0][0] = -200;
while (count < m * n) {
switch (type) {
//向右走
case 0:
if (j + 1 >= n || matrix[i][j + 1] == -200) {
type = 1;
continue;
} else j++;
break;
//向下
case 1:
if (i + 1 >= m || matrix[i + 1][j] == -200) {
type = 2;
continue;
} else i++;
break;
//向左
case 2:
if (j - 1 == -1 || matrix[i][j - 1] == -200) {
type = 3;
continue;
} else j--;
break;
//向上
case 3:
if (i - 1 == -1 || matrix[i - 1][j] == -200) {
type = 0;
continue;
} else i--;
break;
}
list.add(matrix[i][j]);
matrix[i][j] = -200;
count++;
}
return list;
}
public static void main(String[] args) {
System.out.printf(new Q54().spiralOrder(new int[][]{{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}).toString());
}
}

36
5.leetcode/src/com/fanxb/common/Q55.java Normal file
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@ -0,0 +1,36 @@
package com.fanxb.common;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Stack;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q55 {
public boolean canJump(int[] nums) {
int n = nums.length;
if (n == 1) {
return true;
}
int val = nums[0];
for (int i = 1; i < nums.length; i++) {
if (val < i) {
//说明走不到这一步，不用继续了
return false;
}
val = Math.max(val, i + nums[i]);
}
return val >= n - 1;
}
public static void main(String[] args) {
System.out.println(new Q55().canJump(new int[]{1, 0, 1, 0}));
}
}

27
5.leetcode/src/com/fanxb/common/Q56.java Normal file
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@ -0,0 +1,27 @@
package com.fanxb.common;
import java.util.Arrays;
import java.util.Comparator;
import java.util.LinkedList;
import java.util.List;
public class Q56 {
public int[][] merge(int[][] intervals) {
Arrays.sort(intervals, Comparator.comparingInt(a -> a[0]));
int length = intervals.length, count = 0;
int[][] res = new int[intervals.length][2];
int[] startArr = intervals[0];
for (int i = 1; i < length; i++) {
int[] temp = intervals[i];
if (temp[0]<=startArr[1]) {
//可以开始合并
startArr[1] = Math.max(startArr[1], temp[1]);
} else {
res[count++] = startArr;
startArr = temp;
}
}
res[count++] = startArr;
return Arrays.copyOf(res, count);
}
}

61
5.leetcode/src/com/fanxb/common/Q57.java Normal file
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@ -0,0 +1,61 @@
package com.fanxb.common;
import java.util.Arrays;
public class Q57 {
public int[][] insert(int[][] intervals, int[] newInterval) {
int length = intervals.length, i = 0, count = 0;
int[][] res = new int[length + 1][2];
if (intervals.length == 0) return new int[][]{newInterval};
if (newInterval[1] < intervals[0][0]) {
//说明放到最前面
res[count++] = newInterval;
for (int[] num : intervals) res[count++] = num;
return res;
}
if (newInterval[0] > intervals[length - 1][1]) {
//说明放到最后
for (int[] num : intervals) res[count++] = num;
res[count++] = newInterval;
return res;
}
for (; i < length; i++) {
//开始找开始插入的位置
if (intervals[i][1] >= newInterval[0]) {
if (newInterval[1] < intervals[i][0]) {
//说明无交叉，新的放到i前面
res[count++] = newInterval;
for (; i < length; i++) res[count++] = intervals[i];
return res;
}
break;
} else {
res[count++] = intervals[i];
}
}
//有交叉，从i开始进行合并
int[] start = new int[]{Math.min(intervals[i][0], newInterval[0]), Math.max(intervals[i][1], newInterval[1])};
i++;
for (; i < length; i++) {
int[] temp = intervals[i];
if (temp[0] <= start[1]) {
//说明存在重叠，进行合并
start[1] = Math.max(temp[1], start[1]);
} else {
//说明不存在重叠了，
res[count++] = start;
break;
}
}
if (i == length) {
//说明循环完了
res[count++] = start;
} else {
//说明还有一段没合并完
for (; i < length; i++) {
res[count++] = intervals[i];
}
}
return Arrays.copyOf(res, count);
}
}

43
5.leetcode/src/com/fanxb/common/Q58.java Normal file
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@ -0,0 +1,43 @@
package com.fanxb.common;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q58 {
public int lengthOfLastWord(String s) {
int count = 0, length = s.length();
boolean lastCharBlank = false;
for (int i = 0; i < length; i++) {
char c = s.charAt(i);
if (c == ' ') {
lastCharBlank = true;
} else {
if (lastCharBlank) count = 0;
count++;
lastCharBlank = false;
}
}
return count;
}
public int lengthOfLastWord1(String s) {
int length = s.length(), i;
// find last word's first char index
for (i = length - 1; i >= 0; i--) {
if (s.charAt(i) != ' ') break;
}
// cal last word count
for (int j = i - 1; j >= 0; j--) {
if (s.charAt(j) == ' ') return i - j;
}
return i + 1;
}
public static void main(String[] args) {
System.out.println(new Q58().lengthOfLastWord(" asdfasdfasdf"));
}
}

37
5.leetcode/src/com/fanxb/common/Q6.java
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@ -1,5 +1,7 @@
package com.fanxb.common;
import java.util.Arrays;
public class Q6 {
public String convert(String s, int numRows) {
if (numRows == 1) {
@ -39,7 +41,40 @@ public class Q6 {
return new String(strs);
}
public String convert1(String s, int numRows) {
int length = s.length();
if (length <= 1 || numRows == 1) return s;
int nSize = numRows * 2 - 2;
int lineNum = (numRows - 1) * (length / nSize + 1);
char[][] chars = new char[numRows][lineNum];
for (int i = 0; i < numRows; i++) Arrays.fill(chars[i], ' ');
int count = 0, m = 0, n = 0;
for (int i = 0; i < length; i++) {
chars[m][n] = s.charAt(i);
count++;
if (count == nSize) {
count = 0;
m--;
n++;
} else if (count < numRows) {
m++;
} else {
m--;
n++;
}
}
StringBuilder builder = new StringBuilder();
for (int i = 0; i < numRows; i++) {
for (int j = 0; j < lineNum; j++) {
if (chars[i][j] != ' ') {
builder.append(chars[i][j]);
}
}
}
return builder.toString();
}
public static void main(String[] args) {
System.out.println(new Q6().convert("PAYPALISHIRING", 4));
System.out.println(new Q6().convert1("PAYPALISHIRING", 4));
}
}

25
5.leetcode/src/com/fanxb/common/Q71.java Normal file
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@ -0,0 +1,25 @@
package com.fanxb.common;
import java.util.List;
import java.util.Stack;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Q71 {
public String simplifyPath(String path) {
Stack<String> stack = new Stack<>();
List<String> strs = Stream.of(path.split("/+")).filter(item -> !item.isEmpty()).collect(Collectors.toList());
for (String str : strs) {
switch (str) {
case ".":
break;
case "..":
if (!stack.isEmpty()) stack.pop();
break;
default:
stack.push(str);
}
}
return stack.isEmpty() ? "/" : stack.stream().map(item -> "/" + item).collect(Collectors.joining());
}
}

28
5.leetcode/src/com/fanxb/common/Q73.java Normal file
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@ -0,0 +1,28 @@
package com.fanxb.common;
import java.util.Arrays;
public class Q73 {
public void setZeroes(int[][] matrix) {
int m = matrix.length, n = matrix[0].length;
//行是否有0
int[] cache1 = new int[m];
//列是否有0
int[] cache2 = new int[n];
for (int i = 0; i < m; i++)
for (int j = 0; j < n; j++)
if (matrix[i][j] == 0) {
cache1[i] = 1;
cache2[j] = 1;
}
for (int i = 0; i < m; i++)
for (int j = 0; j < n; j++)
if (cache1[i] == 1 || cache2[j] == 1)
matrix[i][j] = 0;
}
public static void main(String[] args) {
}
}

30
5.leetcode/src/com/fanxb/common/Q76.java
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@ -51,6 +51,36 @@ public class Q76 {
return start < 0 ? "" : s.substring(start, end + 1);
}
public String minWindow(String s, String t) {
int sSize = s.length(), needCount = t.length();
int[] map = new int[128];
for (int i = 0; i < needCount; i++) map[t.charAt(i)]++;
int l = 0, r = 0, minL = 0, minR = sSize;
while (r < sSize) {
char temp = s.charAt(r);
if (map[temp] > 0) needCount--;
map[temp]--;
if (needCount == 0) {
//说明包含了所有元素,开始把l向右移动直到刚好包含所有元素
while (needCount == 0) {
temp = s.charAt(l);
if (map[temp] == 0) {
//说明l这个位置刚好，
if ((r - l) < (minR - minL)) {
minL = l;
minR = r;
}
needCount++;
}
map[temp]++;
l++;
}
}
r++;
}
return minR == sSize ? "" : s.substring(minL, minR + 1);
}
public static void main(String[] args) {
System.out.println(solution("a", "aa"));

67
5.leetcode/src/com/fanxb/common/Q92.java Normal file
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@ -0,0 +1,67 @@
package com.fanxb.common;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Stack;
/**
* Created with IntelliJ IDEA
*
* @author fanxb
* Date: 2020/6/9 15:10
*/
public class Q92 {
public class ListNode {
int val;
ListNode next;
ListNode() {
}
ListNode(int val) {
this.val = val;
}
ListNode(int val, ListNode next) {
this.val = val;
this.next = next;
}
}
public ListNode reverseBetween(ListNode head, int left, int right) {
if (left == right) {
return head;
}
//node1 left位置前一个节点，node2 right位置后一个指针
ListNode node1 = null, leftNode = null, node2 = null, rightNode = null;
ListNode last = null, temp = head, next = null;
int count = 0;
while (temp != null) {
count++;
next = temp.next;
if (left == count) {
node1 = last;
leftNode = temp;
}
if (right == count) {
node2 = next;
rightNode = temp;
}
if (count > left && count <= right) {
temp.next = last;
}
last = temp;
temp = next;
}
leftNode.next = node2;
if (node1 != null) {
node1.next = rightNode;
} else {
head = rightNode;
}
return head;
}
}