Cod sursa(job #422972)
Utilizator | Data | 23 martie 2010 13:04:11 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.24 kb |
#include<fstream.h>
int n,i,j,k=0;
char s[2000001];
int main()
{ifstream f("ciur.in");ofstream g("ciur.out");f>>n;
for(i=2;i<=n;i++)
s[i]=1;
for(i=2;i<=n;i++)
{if(s[i]==1)
{k++;
for(j=i+i;j<=n;j+=i) s[j]=0;}}g<<k;
return 0;}