快速幂

快速计算a^b

防止超时

#include <bits/stdc++.h>using namespace std;long long powmod(int a, int b);int main(){    int a, b;    cin >> a >> b;    cout << powmod(a, b) << endl;    return 0;}long long powmod(int a, int b){    long long  cases, k;    cases = 1;    k = a;    while(b > 0)    {    if(b%2) cases *= k;    k *= k;    b /= 2;    }    return cases;}