Jump Game

Jump Game

问题：

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.

思路：

　　贪心算法，每一步都看能达到的最大地点

我的代码：

public class Solution {
    public boolean canJump(int[] A) {
        if(A == null || A.length <= 1)    return true;
        int left = 0;
        int right = 0;
        int max = 0;
        int len = A.length;
        while(left <= right)
        {
            max = Math.max(left+A[left],max);
            if(left == right)
            {
                if(max >= len - 1) return true;
                if(max <= right)    return false;
                left = right + 1;
                right = max;
            }
            else
                left++;
        }
        return false;
    }
    
}

他人代码：

    public boolean canJump(int[] A) {
        if (A == null) {
            return false;
        }
        int len = A.length;
        int right = 0;        
        for (int i = 0; i < A.length; i++) {
            right = Math.max(right, i + A[i]);
            if (right == len - 1) {
                return true;
            }
            if (i == right) {
                return false;
            }
        }
        return true;
    }

学习之处：

• 每一步都维护一个能到达的最右侧的位置