add

5.leetcode/src/com/fanxb/common/Q45.java

@@ -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){
+                steps++;
+                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) {
+    }
+}