Cod sursa(job #2041367)
Utilizator | Data | 17 octombrie 2017 10:10:50 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 90 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.42 kb |
#include <cstdio>
using namespace std;
int main()
{
freopen("ciur.in", "r", stdin);
freopen("ciur.out", "w", stdout);
char ciur[2000001];
int n;
scanf("%d ", &n);
int nr=0;
ciur[1]=1;
for(int i=2; i<=n;i++)
if(ciur[i]==0)
{
nr++;
for(int d=i; d<=n; d+=i)
ciur[d]=1;
}
printf("%d", nr);
return 0;
}