Cod sursa(job #1887020)
Utilizator | Data | 21 februarie 2017 12:06:36 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | c | Status | done |
Runda | Arhiva educationala | Marime | 0.45 kb |
#include <stdio.h>
#include <stdlib.h>
char ciur[2000001];
int main()
{
FILE*fin,*fout;
long long n,i,j,nr=0;
fin = fopen("ciur.in" ,"r");
fout = fopen("ciur.out" ,"w");
fscanf(fin, "%lld" ,&n);
for(i=2;i<=n;i++){
if(ciur[i]==0){
nr++;
for(j=i*i;j<=n;j+=i)
ciur[j]=1;
}
}
fprintf(fout, "%lld\n" ,nr);
fclose(fin);
fclose(fout);
return 0;
}