leetcode292 : Nim Game

1、原题如下
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.

2、解题如下：

class Solution {public:    bool canWinNim(int n) {        if(n%4==0)            return false;        else            return true;    }};//我们把4叫做关键点，抢到就赢了~

3、总结
这道题其实就是小学奥数中比较简单的一类策略类问题。如果没有思路，请自行脑补小学奥数~