Cod sursa(job #171219)
| Utilizator |  Ghiuta Alex ghiutaalex |
Data | 3 aprilie 2008 21:17:18 |
|---|---|---|---|
| Problema | Ciurul lui Eratosthenes | Scor | 100 |
| Compilator | cpp | Status | done |
| Runda | Arhiva educationala | Marime | 0.33 kb |
#include<stdio.h>
#include<string.h>
#define M 2000005
long n,r;
char c[M];
FILE*f=fopen("ciur.in","r");
FILE*g=fopen("ciur.out","w");
int main()
{long i,j;
fscanf(f,"%ld",&n);
memset(c,'1',n);
for(i=2;i<=n;i++)
{if(c[i]=='1') {r++;
for(j=i;j<=n;j+=i)
c[j]='0';}}
fprintf(g,"%ld",r);
fcloseall();
return 0;
}