Cod sursa(job #374005)
Utilizator | Data | 15 decembrie 2009 18:09:01 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.31 kb |
#include<stdio.h>
FILE*f = fopen("ciur.in","r");
FILE*g = fopen("ciur.out","w");
char v[20000005];
int i,n,j,nr;
int main () {
fscanf(f,"%d",&n);
for(i=2;i<=n;i++){
if(v[i]==0){
nr++;
}
for(j=i+i;j<=n;j+=i)
v[j]=1;
}
fprintf(g,"%d",nr);
fclose(f);
fclose(g);
return 0;
}