Cod sursa(job #2058446)
Utilizator | Data | 5 noiembrie 2017 17:36:21 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.3 kb |
#include <bits/stdc++.h>
using namespace std;
ifstream fin("ciur.in");
ofstream fout("ciur.out");
bitset<2000002>p;
int ct=1,n;
int main()
{ fin>>n;
int i,j;
for(i=3;i<=n;i=i+2)
if(p[i]==0)
{ ++ct;
for(j=3*i;j<=n;j+=2*i)
p[j]=1;
}
fout<<ct;
return 0;
}