usaa19exam/sort_pizza.c

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

#define LINE_SIZE 100
#define LIST_SIZE 100


struct pizza {
    char name[LINE_SIZE];
    float prize;
};

char* read_line();

int read_pizza(struct pizza* item);
int read_pizza_list(struct pizza* list);
int compare(const void* a, const void* b);

int main(){

  //struct pizza **list_of_pizzas =(struct pizza**)malloc(LIST_SIZE*sizeof(struct pizza *));
  struct pizza list_of_pizzas[LIST_SIZE];
  memset(list_of_pizzas,0,LIST_SIZE*sizeof(struct pizza));

  int number_of_pizzas = read_pizza_list(list_of_pizzas);

  qsort(list_of_pizzas,number_of_pizzas,sizeof(struct pizza), compare);

  for(int i = 0; i < number_of_pizzas; i++){
    printf("%s", list_of_pizzas[i].name);
    printf("%.6f\n", list_of_pizzas[i].prize);
  }

  

  
  return 0;
}


int read_pizza(struct pizza* item){
  char name_of_dish[LIST_SIZE];
  memset(name_of_dish,0,LINE_SIZE);
  char *name_help = fgets(name_of_dish,LINE_SIZE,stdin);

  if(name_help == NULL || strlen(name_of_dish) == 1){
    return 0;
  }else if (strlen(name_of_dish) == LIST_SIZE - 1 && name_of_dish[LIST_SIZE]!= '\n'){
    printf("name of pizza is too long\n");
    return 0;
  }
  

  if(name_of_dish!= 0){
    strcpy(item->name,name_of_dish);
    
    char  value_help[LIST_SIZE];
    memset(value_help,0,LINE_SIZE);
    char *value_help1 = fgets(value_help,LIST_SIZE,stdin);
    if(value_help1 == NULL || strlen(value_help) == 1){
      return 0;
    }

    float value = strtof(value_help,NULL);
    if(value!=0.0F){
      item->prize=value;
      return 1;
    }
    else return 0;
  }
  else return 0;
}

int read_pizza_list(struct pizza *list){
  
  int counter = 0;

  for (int i=0; i< LIST_SIZE; i++){
      struct pizza item;
      memset(&item,0,sizeof(struct pizza));
      
      int r = read_pizza(&item);
      
      if (r){
          // Ak sa nacitanie podarilo, skopirujte polozku do pola
          memcpy(&list[i],&item,sizeof(struct pizza));
          counter += 1;
      }else{
          //free();
          // Ak sa nacitanie nepodarilo, nasli sme poslednu polozku
          // Prerusim nacitanie
          break;
      }
  }
  return counter;

}
int compare(const void *a, const void *b){

  // a = (struct pizza *)a;
  // b = (struct pizza *)b;
  struct pizza *first =(struct pizza *) a;
  struct pizza *second =(struct pizza *) b;
  if(first->prize == second->prize){
    return strcmp(first->name,second->name);
    
  }else{
   // printf("%0.6f\n",(first->prize) - (second->prize));
   float r = (first->prize) - (second->prize);
   if (r > 0 ) return 1;
   else if ( r < 0) return -1;
   else return 0; 

  }

}