Cod sursa(job #2000475)
Utilizator | Rodica Vasilescu Rodik_Rody | Data | 13 iulie 2017 19:23:53 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | c | Status | done |
Runda | Arhiva educationala | Marime | 0.49 kb |
///Ciurul lui Eratosthenes
#include <stdio.h>
#include <stdlib.h>
#define MAX 2000000
int n;
char ciur[MAX];
int main()
{
freopen("ciur.in", "r", stdin);
freopen("ciur.out", "w", stdout);
int i, j, nr = 0;
scanf("%d",&n);
for ( i = 2; i*i <= n; i++){
if( ciur[i] == 0)
for(j= i*i; j<= n; j +=i)
ciur[j] = 1;
}
for( i = 2; i<= n; i++)
if(ciur[i]==0)
nr++;
printf("%d",nr);
return 0;
}