第一题 快速幂

#include 
     
       using namespace std; typedef long long LL; LL dfs(LL x, LL y, LL N){    if (y == 0)        return 1;    LL ret = dfs(x, y / 2, N);    if (y % 2 == 0)        return ret * ret % N;    return ret * ret * x % N;} int main(){    LL x, y, N;    cin >> x >> y >> N;    cout << dfs(x, y, N) << endl;    return 0;}　　
     

　　第二题二分查找

 

#include 
     
       using namespace std; int main(){    int x;    char c;    vector
      
        arr;    while (true) {        scanf("%d", &x);        arr.push_back(x);        if (getchar() == '\n')            break;    }    scanf("%d", &x);    printf("%u\n", lower_bound(arr.begin(), arr.end(), x) - arr.begin());    return 0;}