2018年海淀区青少年程序设计思维挑战活动普及组详细答案

#include <iostream>#include <cmath>using namespace std;int main(){    int n, day, y;    cin >> n >> day >> y;    cout << ceil((day * 24 * 1.0) / y) << endl;    return 0;}

#include <iostream>using namespace std;int main(){    int n, m;    cin >> n >> m;    int cnt = n;    for(int i = 0; i < n; i++)    {        int k;        cin >> k;        if(0 == k % m)        {            while(k)            {                if(k % 10 == m)                {                    cnt++;                    break;                }                k /= 10;            }        }    }    cout << cnt << endl;    return 0;}

#include<iostream>using namespace std;bool isprime(int n){    for(int i = 2; i * i <= n; i++)    {        if(n % i == 0)        {            return false;        }    }    return true;}int gcd(int a, int b){    return b == 0 ? a : gcd(b, a % b);}int main()  {     int m, n;     cin >> n >> m;     int q = gcd(n, m);     for(int res = q; res >= 2; res--)     {         if(isprime(res))         {             cout << res << endl;             return 0;         }     }     cout << 0 << endl;     return 0; }