[LeetCode] Jump Game

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.

 

解法：贪心算法。时间复杂度O(n), 空间复杂度O(1)

class Solution {
public:
    bool canJump(int A[], int n) {
        if (A == NULL || n <= 0) return false;
        
        int max_pos = 0;
        for (int i = 0; i <= max_pos && max_pos < n; ++i)
            max_pos = i + A[i] > max_pos ? i + A[i] : max_pos;
        
        return max_pos >= n - 1;
    }
};