무한정 정수를 입력받고 평균을 구하기 (realloc 활용)

average.c

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

// Integer data define
typedef struct Data Data;
struct Data {
  int num;
};

// Integer data control functions
Data *NewData(int num); // Create new Integer data
void ViewData(Data *data); // Print one array item
void DeleteData(Data *data); // Free memory from data

// Array struct define
typedef struct Array Array;
struct Array {
  Data **base;
  size_t size;
  size_t count;
};

// Array control functions
Array *NewArray(void); // Create new empty array
void ViewArray(Array *arr); // Print all array items
void ArrayPushData(Array *arr, int num); // Insert Integer data to array
void DeleteArray(Array *arr); // Free memory from array

// requirements functions
void GetIntegerArray(Array *arr); // Get Integer data from user inputs
void PrintIntegerArray(Array *arr); // ViewArray();
double AverageIntegerArray(Array *arr); // Calculate the average of array values

// Main function
int main()
{
  Array *arr = NewArray();
  GetIntegerArray(arr);
  PrintIntegerArray(arr);
  printf("%f\n", AverageIntegerArray(arr));
  DeleteArray(arr);
  return 0;
}

void GetIntegerArray(Array *arr) {
  int t;
  for(;;) {
    scanf("%d", &t);
    if(t == -1) {
      break;
    }
    ArrayPushData(arr, t);
  }
}

void PrintIntegerArray(Array *arr) {
  ViewArray(arr);
  printf("\n");
}

double AverageIntegerArray(Array *arr) {
  int sum = 0;
  for(int i=0;i<arr->count;i++) {
    sum += arr->base[i]->num;
  }
  return (double)sum / (double)arr->count;
}

Data *NewData(int num) {
  Data *data = (Data *)malloc(sizeof(Data));
  data->num = num;
  return data;
}

void ViewData(Data *data) {
  printf("%d\t", data->num);
}

void DeleteData(Data *data) {
  free(data);
}

Array *NewArray(void) {
  Array *arr = (Array *)malloc(sizeof(Array));
  arr->base = (Data **)malloc(sizeof(Data *));
  arr->size = 1;
  arr->count= 0;
  return arr;
}

void ViewArray(Array *arr) {
  Data *data = NULL;
  for(int i=0;i<arr->count;i++) {
    data = arr->base[i];
    ViewData(data);
  }
}

void ArrayPushData(Array *arr, int num) {
  if(arr->count == arr->size) {
    arr->size *= 2;
    arr->base = (Data **)realloc(arr->base, sizeof(Data *)*arr->size);
  }
  arr->base[arr->count] = NewData(num);
  arr->count++;
}

void DeleteArray(Array *arr) {
  Data *data = NULL;
  for(int i=0;i<arr->count;i++) {
    data = arr->base[i];
    DeleteData(data);
  }
  free(arr->base);
  free(data);
}