#include <stdio.h>
#define MAX_SIZE 100
/* Function declaration */
void inputArray(int * arr, int size);
void printArray(int * arr, int size);
/* Sort function declaration */
int sortAscending(int * num1, int * num2);
int sortDescending(int * num1, int * num2);
void sort(int * arr, int size, int (* compare)(int *, int *));
int main()
{
int arr[MAX_SIZE];
int size;
/*
* Input array size and elements.
*/
printf("Enter array size: ");
scanf("%d", &size);
printf("Enter elements in array: ");
inputArray(arr, size);
printf("\n\nElements before sorting: ");
printArray(arr, size);
// Sort and print sorted array in ascending order.
printf("\n\nArray in ascending order: ");
sort(arr, size, sortAscending);
printArray(arr, size);
// Sort and print sorted array in descending order.
printf("\nArray in descending order: ");
sort(arr, size, sortDescending);
printArray(arr, size);
return 0;
}
/**
* Function to take input in array elements.
*
* @arr Array to store input.
* @size Size of the array.
*/
void inputArray(int * arr, int size)
{
// Pointer to last element of array
int * arrEnd = (arr + size - 1);
// (arr++) Input in current array element and move to next element.
// Till last array element (arr <= arrEnd)
while(arr <= arrEnd)
scanf("%d", arr++);
}
/**
* Function to print all array elements.
*
* @arr Array to print.
* @size Size of the array.
*/
void printArray(int * arr, int size)
{
// Pointer to last element of array
int * arrEnd = (arr + size - 1);
// *(arr++) Print current array element and move to next element.
// Till last array element (arr <= arrEnd)
while(arr <= arrEnd)
printf("%d, ", *(arr++));
}
/**
* Function to compare two succesive elements.
* The function returns difference of first and second integer.
*
* @num1 First integer to compare.
* @num2 Second integer to compare.
*
* @return Difference of num1 and num2.
*/
int sortAscending(int * num1, int * num2)
{
return (*num1) - (*num2);
}
/**
* Function to compare two successive elements.
* The function returns difference of second and first parameter.
*
* @num1 First integer to compare.
* @num2 Second integer to compare.
*
* @return Difference of num2 and num1.
*/
int sortDescending(int * num1, int * num2)
{
return (*num2) - (*num1);
}
/**
* Function to sort an array in ascending or descending order.
* This function is used to sort array in both order ascending or
* descending.
*
* @arr Array to sort.
* @size Size of the array.
* @compare Function pointer returning integer and takes two int *
* parameter. The function is called to get arrangement of
* two successive array elements.
*/
void sort(int * arr, int size, int (* compare)(int *, int *))
{
// Pointer to last array element
int * arrEnd = (arr + size - 1);
// Pointer to current array element
int * curElem = arr;
int * elemToSort;
// Iterate over each array element
while(curElem <= arrEnd)
{
elemToSort = curElem;
// Compare each successive elements with current element
// for proper order.
while(elemToSort <= arrEnd)
{
/*
* Compare if elements are arranged in order
* or not. If elements are not arranged in order
* then swap them.
*/
if(compare(curElem, elemToSort) > 0)
{
*curElem ^= *elemToSort;
*elemToSort ^= *curElem;
*curElem ^= *elemToSort;
}
elemToSort++;
}
// Move current element to next element in array.
curElem++;
}
}
