Sample C Program To Implement Quick Sort Using Pointers, Functions & Arrays.

ALGORITHM:

STEP 1: Start the program.
STEP 2: Assign the pointer array *a[100] as global, Read the value of n.
STEP 3: Set a for loop to read the elements of array.
for(i = 0; i < n; i++)
STEP 4: Call the function sort(0, n - 1).
STEP 5: Print the sorted array a.
STEP 6: Stop the program


FUNCTION SORT (int first, int last)

STEP 1: Declare the local variable.
STEP 2: Check if first is less than last.
first < last


STEP 3: If so then assign the following
pivot = a[first]
i = first
j = last


STEP 4: Assign a while loop till the condition.
I < j

STEP 5: Assign a while loop to increment i till
a[i] < pivot and i < last

STEP 6: Assign a while loop to decrement j till
a[j] > pivot and j > first


STEP 7: Check whether i is than j if so then swap the values of a[i] and a[j]
temp = a[i]
a[j] = a[j]
a[j] = temp


STEP 8: Then swap the values of a[j] and a[first].
temp = a[j]
a[j] = a[first]
a[first] =temp

STEP 9: Call another functions sort(first, j - 1) and sort(j + 1, last)


SAMPLE PROGRAM:


#include<stdio.h>
#include<conio.h>

int *a[50], n, i;
void sort(int, int);

void main()
{

clrscr();
printf(" Enter the no of elements: ");
scanf(" %d ", &n);

printf(" Enter the array elements one by one: ");

for(i = 0; i < n; i++)
scanf(" %d ", &a[i]);

printf(" \n UNSORTED ARRAY ELEMENTS ");

for(i = 0; i < n; i++)
printf(" \t %d ", a[i]);

sort(0, n - 1);

printf(" \n SORTED ARRAY ");

for(i = 0; i < n; i++)
printf(" %d ", a[i]);

getch();

}


void sort(int first, int last)
{

int *temp, *pivot, i, j;

if(first < last)
{
pivot = a[first];
i = first;
j = last;
while(i < j)
{
while((a[i] <= pivot) && (I < last))
i++;
while((a[j] >= pivot) && (j > first))
j--;
if(i < j)
{
temp = a[i];
a[i] = a[j];
a[j] = temp;
}
}

temp = a[first];
a[first] = a[j];
a[j] = temp;

sort( first, j – 1 );

sort( j + 1, last );
}

}


OUTPUT:

Enter the number of elements: 6

Enter the array elements one by one
23
45
89
98
09
65

UNSORTED ARRAY ELEMENTS 23 45 89 98 09 65

SORTED ARRAY 09 23 45 65 89 98



ALSO READ:

-- Program To Understand Working Of Address Concept.
-- Program On Use Of Array & Pointer Concept Together.
-- Program On Pointers & 2 - Dimensional Array.
-- Program On Strings Into Array Of Pointers.
-- Program To Accept & Add Ten Numbers Using Pointers.

-- Program To Implement Minimum Spanning Tree Using Functions, Pointers & Structures.
-- Program To Implement 8 Queens Problem Using Arrays, Pointers & Functions.
-- Program To Implement Quick Sort Using Pointers, Functions & Arrays.
-- Program With Algorithm To Implement Bubble Sort Using Pointers.
-- Program To Implement Recursive Algorithm Using Pointers.


-- Program On Strings Into Array Of Pointers.
-- Program On Pointers & 2 - Dimensional Array.
-- Program On Use Of Array & Pointer Concept Together.
-- Program On Arithmetic Calculations Using Pointers.
-- Program To Add Two Numbers Using Pointers.


-- Program To Accept & Add Ten Numbers Using Pointers.


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