int rendez(const void *a, const void *b){
    struct country *pa = (struct country*)a;
    struct country *pb = (struct country*)b;

    if(pa->area > pb->area)
        return -1;
    if(pa->area < pb->area)
        return 1;
    if(pa->area == pb->area){
        return strcmp(pa->name,pb->name);
    }

}

struct country *foo(char *s, int ter, int nep){

    FILE *f;
    f = fopen(s,"rb");
    struct country orszag;
    struct country *orszagok;
    int db=0,i=0;
    float nepsuruseg;
    float ratio = ter/nep;


    while(fread(&orszag,sizeof(struct country),1,f)){
        nepsuruseg = orszag.area / orszag.population;
        if(nepsuruseg > ratio){
            db++;
        }
    }

    orszagok = malloc( (db+1)*sizeof(struct country));
    rewind(f);

    while(fread(&orszag,sizeof(struct country),1,f)){
       nepsuruseg = orszag.area / orszag.population;
        if(nepsuruseg > ratio){
            orszagok[i] = orszag;
            i++;
        }
    }

    qsort(orszagok,db,sizeof(struct country),rendez);

    orszagok[db].area = -1;

    fclose(f);
    return orszagok;
}