Leetcode 题目解析之 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.

设变量maxStep为当前能够跳跃的最大步数，超过数组长度，就表示能够跳出；否则不能跳出。

那么maxStep怎么求得呢？numsi + i 就代表：从当前位置起跳，所能跳跃的最远位置。

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