2021“MINIEYE杯”中国大学生算法设计超级联赛（8）- 1006（GCD Game）

补题链接：​​https://acm.hdu.edu.cn/showproblem.php?pid=7061​​

​​Nim​​ >^<

题解思路可参考​

​​code​​

#include <iostream>

using namespace std;

const int N = 1e7 + 10;

typedef long long ll;

bool st[N];
int primes[N], cnt, sg[N];

void init(){

    st[0] = 1;
    st[1] = 1;

    for (int i = 2; i < N; ++i) {

        if(!st[i]) {
            primes[cnt++] = i;
            sg[i] = 1;
        }
        for (int j = 0; primes[j] <= (N-1) / i; ++j) {

            st[primes[j] * i] = true;

            sg[i * primes[j]] = sg[i] + 1;

            if(i % primes[j] == 0){
                break;
            }

        }
    }
}


int main(){


    int t, n, a;

    ll sum;

    init();


    scanf("%d", &t);

    while(t--){

        scanf("%d", &n);
        sum = 0;

        for (int i = 1; i <= n; ++i) {

            scanf("%d", &a);

            if(a == 1) continue;

            sum ^= sg[a];
        }

        if(sum){

            printf("Alice\n");
        }else{

            printf("Bob\n");
        }
    }

    return 0;
}