Cod sursa(job #153437)
Utilizator | Data | 10 martie 2008 15:41:41 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.27 kb |
#include<fstream.h>
#define nmax 20001
char nr[nmax];
long long i,n,j,x[1002],p=0,k=0;
int main(){
ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=2;i<=n;i++)
if(nr[i]!=1)
{k++;
for(j=i+i;j<=n;j+=i)
nr[j]=1;
}
g<<k;
return 0;
}