Cod sursa(job #654540)
Utilizator | Data | 30 decembrie 2011 17:10:33 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | winners2 | Marime | 0.33 kb |
#include <stdio.h>
int v[2000008];
int main(){
FILE *in,*out;
in=fopen("ciur.in","r");
out=fopen("ciur.out","w");
int n;
fscanf(in,"%d",&n);
int i,j;
for(i=2;i<=n;i++) {
for(j=i+i;j<=n;j+=i) v[j]=1;
}
int prime=0;
for(i=2;i<=n;i++) if(!v[i]) prime++;
fprintf(out,"%d",prime);
fclose(in);
fclose(out);
}