LeetCode: Jump Game II

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.)

class Solution {  
public:  
    int jump(int A[], int n) {  
        // Start typing your C/C++ solution below  
        // DO NOT write int main() function  
        if (n <= 1)  
            return 0;  
          
        int minStep = 0;  
        int maxLen = 0;  
        int i = 0;  
        while (i < n)  
        {  
            if (A[i] > 0)  
                ++minStep;  
            else  
                return 0;  
            // 当前所能达到的最远距离  
            maxLen = A[i] + i;  
            if (maxLen >= n-1)  
                return minStep;  
            int tmp = 0;  
            // 下一步所能达到最远距离的起始坐标  
            for (int j = i + 1; j <= maxLen; ++j)  
            {  
                if (tmp <= A[j] + j)  
                {  
                    tmp = A[j] + j;  
                    i = j;  
                }  
            }  
        }  
          
        return minStep;  
    }  
};