Cod sursa(job #3264570)

Utilizator lucian243Condrea Andrei Lucian lucian243 Data 22 decembrie 2024 14:41:59
Problema Pairs Scor 0
Compilator cpp-64 Status done
Runda Arhiva de probleme Marime 0.55 kb
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
ifstream f("pairs.in");
ofstream g("pairs.out");
long long n,v[100005],cnt,fr[1000005],sol[100005],m[100005],maxi=-1;
int main()
{
    f>>n;
    for(int i=1;i<=n;i++)
    {
        f>>v[i],fr[v[i]]++;
        maxi=max(maxi,v[i]);
    }
    for(int i=maxi;i>=1;i--)
    {
         for(int j=i;j<=maxi;j+=i)
        m[i]+=fr[j];
        sol[i]=m[i]*(m[i]+1)/2;
        for(int j=i*2;j<=maxi;j+=i)
            sol[i]-=sol[j];
    }
    g<<sol[1];
    return 0;
}