Cod sursa(job #1224247)
Utilizator | Data | 30 august 2014 11:48:45 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.34 kb |
#include <stdio.h>
#define MAX 2000005
char prime[MAX];
int n, cnt;
int main(){
int i, j;
freopen("ciur.in", "r", stdin);
freopen("ciur.out", "w", stdout);
scanf("%d", &n);
for(i = 2; i <= n; i++){
if(!prime[i]){
cnt++;
for(j = i + i; j <= n; j+=i){
prime[j] = 1;
}
}
}
printf("%d\n", cnt);
return 0;
}