「力扣」第 292 題：Nim 遊戲（動態規劃）

地址：https://leetcode-cn.com/problems/nim-game/

Java 代碼：

public class Solution {

    public boolean canWinNim(int n) {
        if (n == 0) {
            return false;
        }

        if (n <= 3) {
            return true;
        }

        boolean[] dp = new boolean[n + 1];
        dp[0] = false;
        dp[1] = true;
        dp[2] = true;
        dp[3] = true;
        for (int i = 4; i <= n; i++) {
            dp[i] = dp[i - 1] == false || dp[i - 2] == false || dp[i - 3] == false;
        }
        return dp[n];
    }
}

Java 代碼：

public class Solution2 {

    public boolean canWinNim(int n) {
        if (n == 0) {
            return false;
        }

        if (n <= 3) {
            return true;
        }

        boolean[] dp = new boolean[4];
        dp[0] = false;
        dp[1] = true;
        dp[2] = true;
        dp[3] = true;
        for (int i = 4; i <= n; i++) {
            dp[i % 4] = dp[(i - 1) % 4] == false || dp[(i - 2) % 4] == false || dp[(i - 3) % 4] == false;
        }
        return dp[n % 4];
    }
}

Java 代碼：

public class Solution {

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