55. 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.

Example 1:

Input: [2,3,1,1,4]
Output: true
Explanation: Jump 1 step from index 0 to 1, then 3 steps to the last index.
Example 2:

Input: [3,2,1,0,4]
Output: false
Explanation: You will always arrive at index 3 no matter what. Its maximum jump length is 0, which makes it impossible to reach the last index.

难度：medium

题目：给定一非负整数数组，初始位置在数组第一个元素上。每个数组元素的值表示最大能到达的距离。判断是否可以到达数组最好的位置。

思路：计算每个位置所能到达的最大位置，然后取最大值作为最远到达距离。

Runtime: 4 ms, faster than 93.15% of Java online submissions for Jump Game.

Memory Usage: 40.5 MB, less than 0.98% of Java online submissions for Jump Game.

class Solution {
    public boolean canJump(int[] nums) {
        int steps = nums[0];
        for (int i = 0; i <= steps; i++) {
            steps = Math.max(i + nums[i], steps);
            if (steps >= nums.length - 1) {
                return true;
            }
        }
        
        return false;
    }
}