Cod sursa(job #1125829)
Utilizator | Data | 26 februarie 2014 19:42:49 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.51 kb |
#include <iostream>
#include <fstream>
#include <algorithm>
using namespace std;
int main()
{
int n,i,x,j=0;
bool v[2000001];
ifstream fin("date.in");
ofstream fout("date.out");
fin>>n;
for(i=2;i*i<=n;i++)
{
x=0;
if(v[i]==0)
{
while(i*i+i*x<=n)
{
v[i*i+i*x]=1;
x++;
}
}
}
for(i=2;i<=n;i++)
{
if(v[i]==0) j++;
}
fout<<j;
return 0;
}