Cod sursa(job #1477883)
| Utilizator |  Bodoarca Stefan BodStf |
Data | 27 august 2015 12:16:36 |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 30 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.34 kb |
#include<stdio.h>
#include<malloc.h>
int main()
{
FILE* f1,*f2;
f1=fopen("ciur.in","r");
f2=fopen("ciur.out","w");
int N,count=0,i;
fscanf(f1,"%d",&N);
int *a=(int*)malloc(N*sizeof(int));
for(i=2;i<=N;i++)
{
if(a[i]!=-1)
count++;
for(int j=i*i;j<=N;j+=i)
a[j]=-1;
}
fprintf(f2,"%d\n",count);
return 0;
}