LibreOJ #6165. 一道水题

二次联通门 : LibreOJ #6165. 一道水题

/*
    LibreOJ #6165. 一道水题

    欧拉线性筛
    其实题意就是求区间[1, n]所有数的最小公倍数
    
    那么答案就是所有质因子最大幂次的乘积
    
    水题开心。。
*/
#include <cstdio>
#include <iostream>

#define Max 100000290

int prime[Max], Count;
bool is_prime[Max];

long long Euler_Line_Sieve (const int &N)
{
#define Mod 100000007
    register int i, j; is_prime[1] = true;
    long long res, Answer = 1;    
    for (i = 2; i <= N; ++ i)
    {
        if (is_prime[i] == false)
        {
            prime[++ Count] = i;
            for (res = i; res * (long long) i <= N; res *= i);
            Answer = (Answer * res) % Mod;
        }    
        for (j = 1; j <= Count && i * prime[j] <= N; ++ j)
        {
            is_prime[i * prime[j]] = true;
            if (i % prime[j] == 0)
                break;
        }
    }
#undef Mod
    return Answer;
}
int Main ()
{
    int N;
    scanf ("%d", &N);
    long long Answer = Euler_Line_Sieve (N);

    printf ("%lld", Answer);
    return 0;
}

int ZlycerQan = Main ();
int main (int argc, char *argv[]) {;}