首页 > 其他 > 详细

【leetcode刷题笔记】Jump Game II

时间:2014-07-22 00:11:05      阅读:362      评论:0      收藏:0      [点我收藏+]

Given an array of non-negative integers, you are initially positioned at the first index of the array.

Each element in the array represents your maximum jump length at that position.

Your goal is to reach the last index in the minimum number of jumps.

For example:
Given array A = [2,3,1,1,4]

The minimum number of jumps to reach the last index is 2. (Jump 1 step from index 0 to 1, then 3 steps to the last index.)


 

题解:跟Jump Game十分相像,把原来的boolean数组改成int型数组,用来记录到达i时候最小的步骤数目,遍历j(j<i),考察从j跳到i需要的步骤数目是否小于当前的reach[i],如果小于,就更新reach[i]。最终返回reach[A.length-1]即可。

代码如下:

 1 public class Solution {
 2     public int jump(int[] A) {
 3         if(A == null || A.length == 0)
 4             return 0;
 5         
 6         int[] reach = new int[A.length];
 7         Arrays.fill(reach, Integer.MAX_VALUE);
 8         reach[0] = 0;
 9         
10         for(int i = 1;i < A.length;i++){
11             for(int j = 0;j < i;j++){
12                 if(reach[j] != Integer.MAX_VALUE && j+A[j]>=i){
13                     reach[i] = Math.min(reach[i], reach[j]+1);
14                     break;
15                 }
16             }
17         }
18         
19         return reach[A.length-1];
20     }
21 }

【leetcode刷题笔记】Jump Game II,布布扣,bubuko.com

【leetcode刷题笔记】Jump Game II

原文:http://www.cnblogs.com/sunshineatnoon/p/3858751.html

(0)
(0)
   
举报
评论 一句话评论(0
关于我们 - 联系我们 - 留言反馈 - 联系我们:wmxa8@hotmail.com
© 2014 bubuko.com 版权所有
打开技术之扣,分享程序人生!