link
板子希望考场上不会忘
十年 OI 一场空，不开 ll 见祖宗。

#include <bits/stdc++.h>

using ll = long long;

auto main()->int {
    // std::cin.tie(nullptr)->sync_with_stdio(false);

    ll A, B, P;
    std::cin >> A >> B >> P;

    auto power = [&](ll a, ll b, ll p) {
        ll ans = 1 % p;
        for (; b; b >>= 1) {
            if (b & 1) ans = ans * a % p;
            a = a * a % p;
        }
        return a == 0 ? 0 : ans;
    };

    ll res = power(A, B, P);
    printf("%lld^%lld mod %lld=%lld", A, B, P, res);

    return 0;
}

7min $\textbf{\textcolor{#37A01D}{+3}}$(Luogu) $\textbf{\textcolor{#37A01D}{+1}}$(Nowcoder)