【数组】Jump Game

题目：

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.

思路：

定义一个数来记录某一时刻所能达到的最远距离，遍历数组，每次更新。

/**
 * @param {number[]} nums
 * @return {boolean}
 */
var canJump = function(nums) {
    var n=nums.length,canarr=0;
    for(var i=0;i<=canarr&&canarr<n-1;i++){
        canarr=Math.max(i+nums[i],canarr);
    }

    return canarr>=n-1;
};