【55】Jump Game

题目：

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.

Determine if you are able to reach the last index.

For example:
A = [2,3,1,1,4], return true.

A = [3,2,1,0,4], return false.

思路：

设定一个参数maxreach来记录能达到的最大下标，若最终maxreach大于等于数组最后的下标则return true, 否则return false;

遍历数组，将每个位置能够到达的最大下标与当前maxreach进行比较取最大值。

代码： 

class Solution {
public:
    bool canJump(vector<int>& nums) {
       int maxreach=0;
       for(int i=0;i<nums.size()&&i<=maxreach;i++){
           maxreach=max(i+nums[i],maxreach);
       }
       return maxreach>=nums.size()-1;
    }
   
};