ACM模版

描述

题解

典型的Nim游戏，需要求SG函数，打表暴力即可。

代码

#include <cstdio>

typedef unsigned long long ull;

const int MAX_DIG = 64;

int sg[] = {
  0, 1, 2, 4, 8, 16, 32, 64, 128, 255, 256, 512,
    1024, 2048, 3855, 4096, 8192, 13107, 16384, 21845,
    27306, 32768, 38506, 65536, 71576, 92115, 101470,
    131072, 138406, 172589, 240014, 262144, 272069,
    380556, 524288, 536169, 679601, 847140, 1048576,
    1072054, 1258879, 1397519, 2005450, 2097152, 2121415,
    2496892, 2738813, 3993667, 4194304, 4241896, 4617503,
    5821704, 7559873, 8388608, 8439273, 8861366, 11119275,
    11973252, 13280789, 16777216, 16844349, 17102035,
    19984054, 21979742, 23734709};

int main()
{
    int n;

    while (scanf("%d", &n) == 1)
    {
        ull ans = 0, a;
        for (int i = 0; i < n; i++)
        {
            scanf("%llu\n", &a);
            int h = 0;
            ull d = 1;
            for (int i = 0; i < MAX_DIG; i++)
            {
                // 判断二进制位有几个1
                if ((d << i) & a)
                {
                    h++;
                }
            }
            ans ^= sg[h];
        }
        if (ans == 0)
        {
            puts("L");
        }
        else
        {
            puts("B");
        }
    }
    return 0;
}