Cod sursa(job #1394536)
Utilizator | Data | 20 martie 2015 13:19:34 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.37 kb |
#include <iostream>
#include<fstream>
#define NMax 10000
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
int n,i,j,nr,ciur[NMax];
int main()
{fin>>n;
nr=0;
for(i=2;i<n;i++)
ciur[i]=1;
for(i=2;i*i<=n;i++)
{if(ciur[i]==0)
nr++;
for(j=2;j*i<n;j++)
ciur[i*j]=0;}
for(i=2;i<n;i++)
if(ciur[i]==0)
nr++;
fout << nr;
return 0;
}