Cod sursa(job #1340377)
Utilizator | Bolos Robert euunu | Data | 11 februarie 2015 19:43:52 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | 9neplace | Marime | 0.45 kb |
#include<fstream>
#define N 2000000
using namespace std;
int main()
{
bool ciur[2000001];
ifstream("ciur.in");
ofstream("ciur.out");
long x,i,j;
for(i=2;i<=N;i++)
ciur[i]==true;
fin>>x;
int cnt=0;
for(i=2;i<=x;i++)
if(ciur[i]=true)
{
cnt++
for(j=i+i;j<=x;j=j+i)
ciur[i]==false;
} fout<<cnt;
fin.close();
fout.close();
return 0;}