[LeetCode] Nim Game

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.

思路

1.单堆拈游戏：m个棋子，最多可以拿n个。如果m不为（n+1)倍数，则会胜利。
2.多堆拈游戏：包含 I > 1 堆棋子，在一堆中拿任意多个。如果每堆棋子数量的二进制数位和非0，则会胜利。

Java代码

public class Solution {    public boolean canWinNim(int n) {        return n % 4 != 0;    }}