Cod sursa(job #209316)
Utilizator | Data | 21 septembrie 2008 19:55:29 | |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 30 |
Compilator | cpp | Status | done |
Runda | Arhiva educationala | Marime | 0.33 kb |
#include<stdio.h>
#define dim 1000000
long i,n,j,c;
FILE*f=fopen("ciur.in","r"),*g=fopen("ciur.out","w");
int main()
{
char a[dim];
fscanf(f,"%ld",&n);
for(i=1;i<=n;i++)
a[i]='1';
for(i=2;i<=n;i++)
if(a[i]=='1')
{c++;
for(j=i+i;j<=n;j+=i)
a[j]='0';
}
fprintf(g,"%ld",c);
return 0;
}