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：

题目本身就是一个遍历的问题，直接上代码。 备注：评论中提到如下思路有缺陷，因此我根据
http://blog.csdn.net/lanxu_yy/article/details/11714231的思路二做了改进。

代码：

class Solution {
public:
    bool canJump(int A[], int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int i = 0;
        while(i<n-1)
        {
            if(A[i] == 0)
            {
                break;
            }
            i += A[i];
        };
        
        if(i >= n-1)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
};

优化：

class Solution {
public:
    bool canJump(int A[], int n) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        int pre = 0;
        int cur = n - 1;
        while(true)
        {
            pre = cur;
            for(int i = n - 2; i >= 0; i--)
            {
                if(i + A[i] >= pre)
                {
                    if(cur > i)
                    {
                        cur = i;
                    }
                }
            }
            if(cur == 0)
            {
                return true;
            }
            if(pre == cur)
            {
                return false;
            }
        };
    }
};