Cod sursa(job #387665)

Utilizator vladcatrinaVlad Catrina vladcatrina Data 28 ianuarie 2010 09:47:26
Problema Ciurul lui Eratosthenes Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.31 kb
#include <stdio.h>

FILE*f = fopen("ciur.in","r");
FILE*g = fopen("ciur.out","w");

char c[2000000];
int i,j,n,nr;

int main() {
	
	fscanf(f,"%d",&n);
	
	for(i=2;i<=n;i++){
		if(c[i]==0){
			for(j=i;j<=n;j+=i)
				c[j]=1;
			nr++;
		} 
	}
	fprintf(g,"%d",nr);
	
	fclose(f);
	fclose(g);
	return 0;
}