Cod sursa(job #305727)
Utilizator | Puscas Sergiu harababurel | Data | 18 aprilie 2009 14:22:20 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 20 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.47 kb |
#include <iostream.h>
#include <fstream.h>
#include <math.h>
int main() {
long long n, i, j, v[10000], rez=0;
ifstream f; f.open("ciur.in");
ofstream g; g.open("ciur.out");
f>>n;
for(i=2; i<=n; i++) { v[i]=i; }
for(i=2; i<=sqrt(n); i++) {
if(v[i]!=0) {
for(j=i+1; j<=n; j++) {
if(v[j]%v[i]==0) {
v[j]=0;
}
}
}
}
for(i=1; i<=n; i++) {
if(v[i]!=0) { rez++; }
}
g<<rez;
f.close();
g.close();
return 0;
}