Project Euler Problem 48: Self powers

Self powers

Problem 48

The series, 1¹ + 2² + 3³ + ... + 10¹⁰ = 10405071317.

Find the last ten digits of the series, 1¹ + 2² + 3³ + ... + 1000¹⁰⁰⁰.

C++:

#include <iostream>

using namespace std;

typedef unsigned long long ULL;

const ULL DIGITS10 = 10000000000;

// 模幂函数
ULL powermod(__uint128_t a, int n, ULL m)
{
    __uint128_t res = 1L;
    while(n) {
        if(n & 1L) {
            res *= a;
            res %= m;
        }
        a *= a;
        a %= m;
        n >>= 1;
    }
    return (ULL)res;
}

int main()
{
    long n;
    ULL ans;

    while(cin >> n) {
        ans = 0;
        for(int i=1; i<=n; i++) {
            ans += powermod(i, i, DIGITS10);
            ans %= DIGITS10;
        }

        cout << ans << endl;
    }

    return 0;
}

Python:

print(sum([(x**x)%(10**10) for x in range(1,1001)])%(10**10))