Cod sursa(job #452706)
| Utilizator | Data | 10 mai 2010 19:04:18 | |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 20 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.42 kb |
#include<iostream.h>
#include<fstream.h>
long long a[2000000],i,t,n;
int main()
{ifstream f("ciur.in");
ofstream g("ciur.out");
f>>n;
for(i=1;i<=n-1;i++)
a[i]=i+1;
for(i=1;i<=n;i++){
if((a[i]!=2)&&(a[i]%2==0))a[i]=0;
if((a[i]!=3)&&(a[i]!=0)&&(a[i]%3==0))a[i]=0;
if((a[i]!=5)&&(a[i]!=0)&&(a[i]%5==0))a[i]=0;
if((a[i]!=7)&&(a[i]!=0)&&(a[i]%7==0))a[i]=0;
}
for(i=1;i<=n;i++)
if(a[i]!=0)t++;
g<<t;
}