Cod sursa(job #277810)
Utilizator | Data | 11 martie 2009 22:09:26 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.38 kb |
#include<stdio.h>
#include<math.h>
int main()
{
long int n,i,j,v[2000001],contor=0;
freopen("ciur.in", "r", stdin);
freopen("ciur.out", "w", stdout);
scanf("%ld",&n);
for(i=2;i<=(n/2);i++){
for(j=2;(j*i)<=n;j++)
{v[j*i]=1;}}
for(i=2;i<=n;++i){ if(v[i]!=1) v[i]=0;}
for(i=2;i<=n;i++)
{if(v[i]==0)
contor++;} printf("%ld", contor); return 0;
}