Bang for buck

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_NAZIV (20 + 1)

typedef struct vatromet_st{
    char naziv[MAX_NAZIV];
    unsigned int glasnoca;
    unsigned int cena;
    struct vatromet_st *left;
    struct vatromet_st *right;
}VATROMET;

void tree_init(VATROMET**);
void delete_tree(VATROMET**);
VATROMET* make_vatromet(char*,unsigned int,unsigned int);
void add_to_tree(VATROMET**,VATROMET*);

FILE* safe_open(char*,char*);
void load(FILE*,VATROMET**);
void save(FILE*,VATROMET*,unsigned int,VATROMET**);

int main(int argc,char** argv){
    if(argc != 4){
        printf("Nepravilan poziv programa.");
        return EXIT_FAILURE;
    }else{
        VATROMET* koren,
                * odnos = NULL;
        FILE    * file = safe_open(argv[2],"r");
        tree_init(&koren);
        load(file,&koren);
        fclose(file);
        file = safe_open(argv[3],"w");
        save(file,koren,atoi(argv[1]),&odnos);
        fprintf(file,"\nNajbolji vatromet sa odnosom glasnoce prema ceni od %.2f je:\n%u %s %u",(float)odnos->glasnoca/odnos->cena,odnos->cena,odnos->naziv,odnos->glasnoca);
        fclose(file);
        delete_tree(&koren);
        return EXIT_SUCCESS;
    }
}

void tree_init(VATROMET** koren){
    *koren = NULL;
}

void delete_tree(VATROMET** koren){
    if(*koren != NULL){
        delete_tree(&(*koren)->left);
        delete_tree(&(*koren)->right);
        free(*koren);
    }
}

VATROMET* make_vatromet(char* naziv,unsigned int glasnoca,unsigned int cena){
    VATROMET* new = (VATROMET*)malloc(sizeof(VATROMET));
    if(new == NULL){
        printf("Nije moguce zauzeti memoriju.");
        exit(EXIT_FAILURE);
    }
    strcpy(new->naziv,naziv);
    new->glasnoca = glasnoca;
    new->cena     = cena;
    new->left     = NULL;
    new->right    = NULL;
    return new;
}

void add_to_tree(VATROMET** koren,VATROMET* new){
    if(*koren == NULL){
        *koren = new;
    }else{
        if((*koren)->cena > new->cena){
            add_to_tree(&(*koren)->left,new);
        }else{
            add_to_tree(&(*koren)->right,new);
        }
    }
    return;
}

FILE* safe_open(char* name,char* mode){
    FILE* f = fopen(name,mode);
    if(f == NULL){
        printf("Nije moguce otvoriti datoteku %s.",name);
        exit(EXIT_FAILURE);
    }
    return f;
}

void load(FILE* f,VATROMET** koren){
    char naziv[MAX_NAZIV];
    unsigned int glasnoca,
                 cena;
    while(fscanf(f,"%s %u %u",
                            naziv,
                            &glasnoca,
                            &cena) != EOF){
        add_to_tree(koren,make_vatromet(naziv,glasnoca,cena));
    }
    return;
}

void save(FILE* f,VATROMET* koren,unsigned int max_glasnoca,VATROMET** odnos){
    if(koren != NULL){
        save(f,koren->left,max_glasnoca,odnos);
        if(koren->glasnoca <= max_glasnoca){
            fprintf(f,"%u %s %u\n",koren->cena,koren->naziv,koren->glasnoca);
            if(*odnos == NULL){
                *odnos = koren;
            }else{
                if( ((*odnos)->glasnoca/(*odnos)->cena) < (koren->glasnoca/koren->cena) ){
                    *odnos = koren;
                }
            }
        }
        save(f,koren->right,max_glasnoca,odnos);
    }
}