Cod sursa(job #1695684)

Utilizator dumitrescu_andreiDumitrescu Andrei dumitrescu_andrei Data 27 aprilie 2016 17:31:00
Problema Fractii Scor 10
Compilator cpp Status done
Runda Arhiva de probleme Marime 0.57 kb
#include <fstream>
#include <string.h>

using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int ok[1000001];
int main()
{int n,i,j,r,a,b;
long long s=0;
f>>n;

for(i=2;i*i<=1000000;i++)
{ if(!ok[i])
{
    j=2;
    while(i*j<=1000000)
        ok[i*j]=1,j++;

}

}
for(i=1;i<=n;i++)
    for(j=1;j<=n;j++)
    if(!ok[i]&&!ok[j]&&i!=j) s++;
    else if(!ok[i]&&j%i) s++;
    else if(!ok[j]&&i%j) s++;
    else{
        a=i;
        b=j;
        r=a%b;
        while(r)
            a=b,b=r,r=a%b;
        if(b==1) s++;
    }
g<<s;
}