Cod sursa(job #1549923)
Utilizator | Data | 12 decembrie 2015 22:18:56 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.28 kb |
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
long a[2000001];
int main()
{long N,i;
int S=1,j;
f>>N;
for(i=3;i<=N;i=i+2)
if(a[i]==0)
{S++;
for(j=1;j*i<=N;j=j+2)
a[j*i]=1;}
g<<S;
return 0;}