Cod sursa(job #1509017)
Utilizator | Data | 23 octombrie 2015 13:47:19 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.45 kb |
#include <iostream>
#include <fstream>
using namespace std;
ifstream f("ciur.in");
ofstream g("ciur.out");
int taiat[20000001];
int main()
{
int v[20000001],i,j,k=0,n;
k=0;
f>>n;
for(i=1;i<=n;i++)
v[i]=k+1;
for(i=2;i<=n;i++)
{
if(taiat[i]==0)
for(j=i+i;j<=n;j+=i)
taiat[j]=1;
}
k=0;
for(i=1;i<=n;i++)
if(taiat[i]==0)
k++;
g<<k;
}