python/TangDou/Topic/ksm.cpp

#include <iostream>
using namespace std;
typedef long long LL;
const LL mod = 1e9 + 7;
/*
测试用例：
5 8

结果：
390625
*/
//快速幂
LL ksm(LL a, LL b) {
    LL ans = 1;
    a %= mod;
    while (b) {
        if (b & 1) ans = (ans * a) % mod;
        b >>= 1; //位运算，右移1位，相当于除以2
        a = (a * a) % mod;
    }
    return ans;
}
int main() {
    LL a, b;
    cin >> a >> b;
    printf("%lld\n", ksm(a, b));
    return 0;
}