Cod sursa(job #1753953)

Utilizator bogdanluncasubogdan bogdanluncasu Data 7 septembrie 2016 12:58:45
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.29 kb
Raporteaza aceasta sursa 
#include<iostream>
int n,c;
bool a[2000001];
void ciur(){
	for(int i=2;i<=n;i++){
		if(!a[i]){
			c++;
			for(int j=2*i;j<=n;j+=i){
				a[j]=1;
			}
		}
	}
}
int main(){
	freopen("ciur.in", "r", stdin);
	freopen("ciur.out", "w", stdout);
	scanf("%d",&n);
	ciur();
	printf("%d",c);
}