Statistika ocjena

#include <stdio.h>
#include <ctype.h>

int main(int argc, char **argv)
{
    FILE *fp;
    int a;
    float s;
    int a5=0, a6=0, a7=0, a8=0, a9=0, a10=0;
    fp=fopen("ispit.dat", "r");
    if (fp==NULL) return 0;
    else {
        printf("Otvorena!\n");
        while(!feof(fp)) {
            if (isdigit(getc(fp))) {
                fseek(fp, -1, 1);
                fscanf(fp, "%d", &a);
                if (a<51) a5++;
                else if (a>50 && a<61) a6++;
                else if (a>60 && a<71) a7++;
                else if (a>70 && a<81) a8++;
                else if (a>80 && a<91) a9++;
                else if (a>90 && a<101) a10++;
                else {
                    printf("Nedozvoljen broj bodova!\n");
                    fclose(fp);
                    return 0;
                }

            }
        }
        fclose(fp);
        printf("Zatvorena!\n");
    }
    fp=fopen("analiza.txt", "w");
    if (fp==NULL) return 0;
    else {
        printf("Otvorena!\n");
        s=a5+a6+a7+a8+a9+a10;
        fprintf(fp, "Izvanredan (>90): %dx (%5.2f%%)\n", a10, (a10)/s*100);
        fprintf(fp, "Odlican (81-90): %dx (%5.2f%%)\n", a9, (a9/s)*100);
        fprintf(fp, "Vrlodobar (71-80): %dx (%5.2f%%)\n", a8, (a8/s)*100);
        fprintf(fp, "Dobar (61-70): %dx (%5.2f%%)\n", a7, (a7/s)*100);
        fprintf(fp, "Dovoljan (51-60): %dx (%5.2f%%)\n", a6, (a6/s)*100);
        fprintf(fp, "Nedovoljan (<51): %dx (%5.2f%%)\n", a5, (a5/s)*100);
    }
    fclose(fp);
    printf("Zatvorena!\n");

    return 0;
}