Cod sursa(job #384314)

Utilizator AdrianMarMarinica Adrian-Petre AdrianMar Data 19 ianuarie 2010 21:13:33
Problema Ciurul lui Eratosthenes Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
Raporteaza aceasta sursa 
#include<iostream.h>
#include<fstream.h>
int main()
{long long n, a[1000],b=0, i, j;
fstream f("ciur.in", ios::in);
fstream g("ciur.out", ios::out);
f>>n;
for(i=3; i<=n; i+=2)
	{a[i]=i;a[i+1]=-1;}

for(i=3; i*i<=n; i+=2)
for(j=i; j*i<=n; j++)
	a[i*j]=-1;

for(i=1; i<=n; i++)
	if(a[i]!=-1)
		b++; 
g<<b;}