Cod sursa(job #234854)
Utilizator | Radutoiu Miruna MiryBlue | Data | 22 decembrie 2008 09:30:15 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 0 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.41 kb |
#include<iostream.h>
#include<string.h>
#include<math.h>
#include<fstream.h>
fstream f("ciur.in", ios::in);
fstream g("ciur.out", ios::out);
int main()
{
long k,n,i,j;
unsigned char p[2000001];
f>>n; f.get();
memset(p,'1',2000001);
i=2;
k=0;
while(i<=n)
if(p[i]=='1'){
for(j=i; j<=n;j+i)
p[j]='0';
k++;
}
else i++;
f.close();
g<<k;
g.close();
return 0;
}