Намирница са највише витамина С

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

#define MAX_NAZIV (13 + 1)
#define MAX_VRSTA (10 + 1)

typedef struct namirnica_st{
    char naziv[MAX_NAZIV];
    unsigned int kolicina;
    char vrsta[MAX_VRSTA];
    struct namirnica_st *left;
    struct namirnica_st *right;
}NAMIRNICA;

void tree_init(NAMIRNICA**);
void delete_tree(NAMIRNICA**);
NAMIRNICA* make_namirnica(char*,unsigned int,char*);
void add_to_tree(NAMIRNICA**,NAMIRNICA*);

FILE* safe_open(char*,char*);
void load(FILE*,NAMIRNICA**);
void save(FILE*,NAMIRNICA*);
void save_max(FILE*,NAMIRNICA*);

int main(int argc,char** argv){
    if(argc != 3){
        printf("Nepravilan poziv programa.\n");
        return EXIT_FAILURE;
    }else{
        NAMIRNICA* koren;
        FILE* file = safe_open(argv[1],"r");
        tree_init(&koren);
        load(file,&koren);
        fclose(file);
        file = safe_open(argv[2],"w");
        save(file,koren);
        save_max(file,koren);
        fclose(file);
        delete_tree(&koren);
        return EXIT_SUCCESS;
    }
}

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

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

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

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

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

void load(FILE *f,NAMIRNICA** koren){
    char naziv[MAX_NAZIV],
         vrsta[MAX_VRSTA];
    unsigned int kolicina;
    while(fscanf(f,"%s %u %s",
                             naziv,
                             &kolicina,
                             vrsta) != EOF){
        add_to_tree(koren,make_namirnica(naziv,kolicina,vrsta));
    }
    return;
}

void save(FILE* f,NAMIRNICA* koren){
    if(koren != NULL){
        save(f,koren->left);
        fprintf(f,"%3u %-13s %s\n",
                                koren->kolicina,
                                koren->naziv,
                                koren->vrsta);
        save(f,koren->right);
    }
}

void save_max(FILE* f,NAMIRNICA* koren){
    if(koren->left != NULL){
        save_max(f,koren->left);
        return;
    }
    fprintf(f,"\n%s %u",koren->naziv,koren->kolicina);
}