Cod sursa(job #2007603)

Utilizator Mircea_DonciuDonciu Mircea Mircea_Donciu Data 3 august 2017 14:10:59
Problema Mins Scor 100
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.78 kb
#include <cstdio>
#include <algorithm>
using namespace std;
int divizori[1000005], v[1000005];
int main()
{
    freopen("mins.in", "r", stdin);
    freopen("mins.out", "w", stdout);
    int n, m, i;
    long long x, j;
    scanf("%d%d", &n, &m);
    m--; n--;
    if(n>m)
        swap(n,m);
    for(i=2; i<=n; i++)
    {
        if(!divizori[i])
        {
            for (j=i; j<=n; j+=i)
                divizori[j]++;
            for (j=1LL*i*i; j<=n; j += i * i)
                v[j]=1;
        }
    }
    x = 1LL * n * m;
    for (i=2; i<=n; i++)
    {
        if (!v[i])
        {
            if (divizori[i]%2)
                x-=1LL*(n/i)*(m/i);
            else
                x+=1LL*(n/i)*(m/i);
        }
    }
    printf("%lld", x);
    return 0;
}