Cod sursa(job #248639)
Utilizator | Data | 26 ianuarie 2009 13:06:44 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.27 kb |
#include<fstream.h>
ifstream f("ciur.in");
ofstream g("ciur.out");
const int N=2000001;
int main()
{int n,i,j,x=0;
f>>n;
char c[N]={0};
for(i=2;i*i<=n;i++)
if(c[i]==0)
x++;
for(j=i*i;j<=n;j=j+i)
c[j]=1;
g<<x;
f.close();g.close();
return 0;}