Hankson 的趣味题

#include <iostream>

using namespace std;

int gcd(int a, int b) {
    return b ? gcd(b, a % b) : a;
}

int main() {
    int t;
    cin >> t;

    while (t -- ) {
        int a0, a1, b0, b1;
        cin >> a0 >> a1 >> b0 >> b1;

        int cnt = 0;

        for (int i = 1; i * i <= b1; i ++ )

            if (b1 % i == 0) {
                if (i % a1 == 0 && gcd(i / a1, a0 / a1) == 1 && gcd(b1 / b0, b1 / i) == 1)
                    cnt ++ ;

                if (i * i != b1) {
                    int I = b1 / i;

                    if (I % a1 == 0 && gcd(I / a1, a0 / a1) == 1 && gcd(b1 / b0, b1 / I) == 1)
                        cnt ++ ;
                }
            }

        cout << cnt << endl;
    }

    return 0;
}

Semi-prime H-numbers

#include <iostream>

using namespace std;

const int N = 1e6 + 10;

int H_number[N];

void init(int n) {
    for (int i = 5; i <= 1e6 + 1; i += 4) {

        for (int j = 5; j <= 1e6 + 1; j += 4) {

            int x = i * j;

            if (x > N)
                break;

            if (H_number[i] == 0 && H_number[j] == 0)
                H_number[x] = 1;
            else
                H_number[x] = -1;
        }
    }

    int cnt = 0;

    for (int i = 0; i <= 1e6 + 1; i ++ ) {

        if (H_number[i] == 1)
            cnt ++ ;
        H_number[i] = cnt;
    }
}

int main() {
    init(N);

    int n;

    while (cin >> n && n) {
        printf("%d %d\n", n, H_number[n]);
    }

    return 0;
}

转圈游戏

#include <iostream>

using namespace std;

typedef long long LL;

int qmi(int a, int k, int p) {
    int res = 1 % p;

    while (k) {
        if (k & 1)
            res = (LL)res * a % p;
        a = (LL)a * a % p;
        k >>= 1;
    }

    return res;
}

int main() {
    int n, m, k, x;
    cin >> n >> m >> k >> x;
    int X = qmi(10, k, n);
    printf("%d\n", (x + m * X) % n);
    return 0;
}