Cod sursa(job #763264)
Utilizator | Cimpu Cristina cristina.cimpu | Data | 1 iulie 2012 15:47:34 |
---|---|---|---|
Problema | Ciurul lui Eratosthenes | Scor | 100 |
Compilator | c | Status | done |
Runda | Arhiva educationala | Marime | 0.41 kb |
#include <stdio.h>
#define max 2000000
int main() {
FILE *f, *g;
int N, i, j, nr;
char prim[max];
f = fopen("ciur.in", "r");
g = fopen("ciur.out", "w");
fscanf(f, "%d", &N);
for (i = 2; i <= N; i++) {
prim[i] = 1;
}
for (i = 2; i <= N; i++) {
if (prim[i] == 1) {
nr++;
for (j = i + i; j <= N; j = j + i) {
prim[j] = 0;
}
}
}
fprintf(g, "%d", nr);
fclose(f);
fclose(g);
return 0;
}