Cod sursa(job #386844)
Utilizator | Barbulescu Daniel 1994 | Data | 26 ianuarie 2010 10:42:23 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.46 kb |
#include <stdio.h>
using namespace std;
char c[10000000];
int main()
{
FILE *fin,*fout;
fin=fopen("ciur.in","r");
fout=fopen("ciur.out","w");
long long n;
fscanf(fin,"%lld",&n);
c[0]=1;
c[1]=1;
for (int i=2;i<n;i++)
if (c[i]==0)
for (int j=2*i;j<n;j+=i)
c[j]=1;
int nr=0;
for (int i=2;i<n;i++)
if (c[i]==0)
nr++;
fprintf(fout,"%d ",nr);
return 0;
}