292Nim Game

题目链接：https://leetcode.com/problems/nim-game/

题目：

You are playing the following Nim Game with your friend: There is a heap of stones on the table, each time one of you take turns to remove 1 to 3 stones. The one who removes the last stone will be the winner. You will take the first turn to remove the stones.Both of you are very clever and have optimal strategies for the game. Write a function to determine whether you can win the game given the number of stones in the heap.For example, if there are 4 stones in the heap, then you will never win the game: no matter 1, 2, or 3 stones you remove, the last stone will always be removed by your friend.Hint:If there are 5 stones in the heap, could you figure out a way to remove the stones such that you will always be the winner?

解题思路：
这题和我去面蓝讯时的智力题一模一样，那时候没答出来。
只有让最后一次剩下3块石头，才能保证自己一定能赢。如果石头是4块，就一定赢不了。将石头块数扩展到5，6 ,7 ,8 块时发现，当石头快数是 4 的倍数时，一定没法赢。

代码实现：

public class Solution {    public boolean canWinNim(int n) {        if(n % 4 == 0)            return false;        else            return true;    }}

60 / 60 test cases passed.Status: AcceptedRuntime: 0 ms