add

5.leetcode/src/com/fanxb/common/Q46.java

@@ -1,5 +1,9 @@
 package com.fanxb.common;
 
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Stack;
+
 /**
  * Created with IntelliJ IDEA
  *
@@ -8,20 +12,38 @@ package com.fanxb.common;
  */
 public class Q46 {
 
-    public int translateNum(int num) {
+    public List<List<Integer>> permute(int[] nums) {
-        String str = String.valueOf(num);
+        List<List<Integer>> res = new ArrayList<>();
-        //a=f(0),b=f(1)
+        dfs(nums, new Stack<>(), new boolean[nums.length], res);
-        int a = 1, b = 1, sum = 1;
+        return res;
-        for (int i = 1, length = str.length(); i < length; i++) {
+    }
-            String temp = str.substring(i - 1, i + 1);
+
-            sum = temp.compareTo("10") >= 0 && temp.compareTo("25") <= 0 ? a + b : b;
+    /**
-            a = b;
+     * dfs搜索
-            b = sum;
+     *
+     * @param nums 源数组
+     * @param temp 记录已选择的数字
+     * @param used 记录已选择数字的位置
+     * @param res  保存结果
+     * @author fanxb
+     * date 2022/3/11 14:20
+     */
+    public void dfs(int[] nums, Stack<Integer> temp, boolean[] used, List<List<Integer>> res) {
+        if (temp.size() == nums.length) {
+            res.add(new ArrayList<>(temp));
+        }
+        for (int i = 0; i < nums.length; i++) {
+            if (!used[i]) {
+                temp.push(nums[i]);
+                used[i] = true;
+                dfs(nums, temp, used, res);
+                used[i] = false;
+                temp.pop();
+            }
         }
-        return sum;
     }
 
     public static void main(String[] args) {
-        System.out.println(new Q46().translateNum(12258));
+        System.out.println(new Q46().permute(new int[]{1, 1, 2}));
     }
 }

5.leetcode/src/com/fanxb/common/Q47.java

@@ -0,0 +1,58 @@
+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 Q47 {
+
+    public List<List<Integer>> permuteUnique(int[] nums) {
+        List<List<Integer>> res = new ArrayList<>();
+        Arrays.sort(nums);
+        dfs(nums, new Stack<>(), new boolean[nums.length], res);
+        return res;
+    }
+
+    /**
+     * dfs搜索
+     *
+     * @param nums 源数组
+     * @param temp 记录已选择的数字
+     * @param used 记录已选择数字的位置
+     * @param res  保存结果
+     * @author fanxb
+     * date 2022/3/11 14:20
+     */
+    public void dfs(int[] nums, Stack<Integer> temp, boolean[] used, List<List<Integer>> res) {
+        if (temp.size() == nums.length) {
+            res.add(new ArrayList<>(temp));
+        }
+        for (int i = 0; i < nums.length; ) {
+            if (!used[i]) {
+                temp.push(nums[i]);
+                used[i] = true;
+                dfs(nums, temp, used, res);
+                used[i] = false;
+                temp.pop();
+                int tempI = i;
+                while (i < nums.length && nums[tempI] == nums[i]) {
+                    i++;
+                }
+            } else {
+                i++;
+            }
+
+        }
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q47().permuteUnique(new int[]{1, 1, 2}));
+    }
+}

5.leetcode/src/com/fanxb/common/Q62.java

@@ -0,0 +1,29 @@
+package com.fanxb.common;
+
+import java.util.Arrays;
+
+/**
+ * TODO
+ *
+ * @author fanxb
+ * @date 2022/3/11 15:28
+ */
+public class Q62 {
+    public int uniquePaths(int m, int n) {
+        int[][] f = new int[m][n];
+        Arrays.fill(f[0], 1);
+        for (int i = 0; i < m; i++) {
+            f[i][0] = 1;
+        }
+        for (int i = 1; i < m; i++) {
+            for (int j = 1; j < n; j++) {
+                f[i][j] = f[i - 1][j] + f[i][j - 1];
+            }
+        }
+        return f[m - 1][n - 1];
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q62().uniquePaths(3, 7));
+    }
+}

5.leetcode/src/com/fanxb/common/Q63.java

@@ -0,0 +1,40 @@
+package com.fanxb.common;
+
+import java.util.Arrays;
+
+/**
+ * TODO
+ *
+ * @author fanxb
+ * @date 2022/3/11 15:28
+ */
+public class Q63 {
+    public int uniquePathsWithObstacles(int[][] obstacleGrid) {
+        int m = obstacleGrid.length, n = obstacleGrid[0].length;
+        int[][] f = new int[m][n];
+        for (int i = 0; i < m; i++) {
+            if (obstacleGrid[i][0] == 1) {
+                break;
+            }
+            f[i][0] = 1;
+        }
+        for (int i = 0; i < n; i++) {
+            if (obstacleGrid[0][i] == 1) {
+                break;
+            }
+            f[0][i] = 1;
+        }
+        for (int i = 1; i < m; i++) {
+            for (int j = 1; j < n; j++) {
+                if (obstacleGrid[i][j] == 0) {
+                    f[i][j] = f[i - 1][j] + f[i][j - 1];
+                }
+            }
+        }
+        return f[m - 1][n - 1];
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q63().uniquePathsWithObstacles(new int[][]{{0, 1}, {0, 0}}));
+    }
+}

5.leetcode/src/com/fanxb/common/Q70.java

@@ -0,0 +1,26 @@
+package com.fanxb.common;
+
+/**
+ * 定义f(n)表示爬n级台阶的方法
+ *
+ * @author fanxb
+ * @date 2022/3/11 15:55
+ */
+public class Q70 {
+    public int climbStairs(int n) {
+        if (n <= 2) {
+            return n;
+        }
+        int last1 = 1, last2 = 2, res = 2;
+        for (int i = 3; i <= n; i++) {
+            res = last1 + last2;
+            last1 = last2;
+            last2 = res;
+        }
+        return res;
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q70().climbStairs(5));
+    }
+}

5.leetcode/src/com/fanxb/common/Q78.java

@@ -0,0 +1,43 @@
+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 Q78 {
+
+    public List<List<Integer>> subsets(int[] nums) {
+        List<List<Integer>> res = new ArrayList<>();
+        dfs(nums, 0, new Stack<>(), res);
+        return res;
+    }
+
+    /**
+     * dfs搜索
+     *
+     * @param nums 源数组
+     * @param temp 记录已选择的数字
+     * @param res  保存结果
+     * @author fanxb
+     * date 2022/3/11 14:20
+     */
+    public void dfs(int[] nums, int index, Stack<Integer> temp, List<List<Integer>> res) {
+        res.add(new ArrayList<>(temp));
+        for (int i = index; i < nums.length; i++) {
+            temp.push(nums[i]);
+            dfs(nums, i + 1, temp, res);
+            temp.pop();
+        }
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q78().subsets(new int[]{1}));
+    }
+}

5.leetcode/src/com/fanxb/common/Q90.java

@@ -0,0 +1,48 @@
+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 Q90 {
+
+    public List<List<Integer>> subsetsWithDup(int[] nums) {
+        List<List<Integer>> res = new ArrayList<>();
+        Arrays.sort(nums);
+        dfs(nums, 0, new Stack<>(), res);
+        return res;
+    }
+
+    /**
+     * dfs搜索
+     *
+     * @param nums 源数组
+     * @param temp 记录已选择的数字
+     * @param res  保存结果
+     * @author fanxb
+     * date 2022/3/11 14:20
+     */
+    public void dfs(int[] nums, int index, Stack<Integer> temp, List<List<Integer>> res) {
+        res.add(new ArrayList<>(temp));
+        for (int i = index; i < nums.length; ) {
+            temp.push(nums[i]);
+            dfs(nums, i + 1, temp, res);
+            temp.pop();
+            int tempI = i;
+            while (i < nums.length && nums[i] == nums[tempI]) {
+                i++;
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        System.out.println(new Q90().subsetsWithDup(new int[]{1, 2, 2}));
+    }
+}