快速幂

不开long long见祖宗👀

洛谷P1226

#include <stdio.h>

#define LL long long
#define IN freopen("in.txt", "r", stdin)
#define OUT freopen("out.txt", "w", stdout)
#define scan(x) scanf("%d", &x)
#define sqr(x) (x) * (x)
#define f(i, a, b) for (int i = a; i <= b; i++)
#define pn(x) printf("%d", x)
#define pr1(x) printf("Case %d: ", x)
#define pn1(x) printf("Case %d:\n", x)
#define pr2(x) printf("Case #%d: ", x)
#define pn2(x) printf("Case #%d:\n", x)
#define lowbit(x) (x & (-x))

int quikpower (int a,int b,int p){
    LL ans = 1, base = a;
    while(b>0){
        if(b&1){
            ans *= base;
            ans %= p;
        }
        base *= base;
        base %= p;
        b >>= 1;
    }
    return (int)ans%p;
}

int main()
{
    int a, b, p;
    scan(a);
    scan(b);
    scan(p);
    printf("%d^%d mod %d=", a, b, p);
    pn(quikpower(a,b,p));
    return 0;
}