LeetCode55 Jump Game 跳跳游戏

题目描述：
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.
思路：
同第45题，我们同样使用贪心算法完成本题，代码如下：

class Solution {
public:
    bool canJump(vector<int>& nums) {
        if (nums.size() == 1) return true;
        int pos = 0;
        while (1){
            int maxJump = 0, newPos = pos;
            for (int i = pos; i <= pos+nums[pos]; i++){
                if (maxJump < i + nums[i]){
                    maxJump = i + nums[i]; newPos = i;
                }
                if (maxJump >= nums.size()-1) return true;
            }
            if (pos == newPos) return false;
            else pos = newPos;
        }
    }
};