/*
*  Author: klchang
*  Description:
        Test the memory management functions in heap.
*  Created date: 2016.7.29
*/

#include <stdio.h>  // scanf, printf
#include <stdlib.h> // malloc, calloc, realloc, free
#include <string.h> // memset

#define SIZE 10

// Input Module
int* inputModule(int* ptrCount)
{
    int* arr, d, i = 0;
    int length = SIZE;

    // Apply malloc()
    arr = (int*)malloc(SIZE * sizeof(int));
    memset(arr, 0, length * sizeof(int));

    // Input module
    printf("Input numbers until you input zero: \n");
    while (1) {
        scanf("%d", &d);
        // count
        *ptrCount += 1;
        if (0 == d) {
            arr[i] = 0;
            break;
        } else {
            arr[i++] = d;
        }
        if (i >= length) {
            // Apply realloc()
            realloc(arr, 2*length*sizeof(int));
            memset(arr+length, 0, length * sizeof(int));
            length *= 2;
        }
    }

    return arr;
}


// Output module
void outputModule(int* arr, int* ptrCount)
{
    int i;

    printf("\nOutput all elements that have been input: \n");
    for(i = 0; i < *ptrCount; i++) {
        if (i && i%5 == 0)
            printf("\n");
        printf("\t%d", *(arr+i));
    }

    // Release heap memory space
    free(ptrCount);
    free(arr);
}

int main()
{
    int i = 0;
    int* ptrCount;
    int* arr;

    // Apply calloc()
    ptrCount = (int *)calloc(1, sizeof(int));
    // Input Module
    arr = inputModule(ptrCount);
    // Before free() function, output the count of input numbers
    printf("\n\nBefore using free() function, Count: %d", *ptrCount);
    // Output Module
    outputModule(arr, ptrCount);
    // After free() function, output the count of input numbers
    printf("\n\nAfter using free() function, Count: %d", *ptrCount);

    return 0;
}