/*
Summary: Quicksort is a very efficient
sorting algorithm.It has two phases:
-the partition phase and
-the sort phase.
Most of the work is done in the partition phase -
it works out where to divide the work. The sort phase simply
sorts the two smaller problems
that are generated in the partition phase.
Complexity: O(n·log n)
*/
#include
void quicksort (int [], int, int);
int main()
{
int list[50];
int size, i;
clrscr();
printf("Enter the number of elements: ");
scanf("%d", &size);
printf("Enter the elements to be sorted:\n");
for (i = 0; i < size; i++)
{
scanf("%d", &list[i]);
}
quicksort(list, 0, size - 1);
printf("After applying quick sort\n");
for (i = 0; i < size; i++)
{
printf("%d ", list[i]);
}
printf("\n");
getch();
return 0;
}
void quicksort(int list[], int low, int high)
{
int pivot, i, j, temp;
if (low < high)
{
pivot = low;
i = low;
j = high;
while (i < j)
{
while (list[i] <= list[pivot] && i <= high)
{
i++;
}
while (list[j] > list[pivot] && j >= low)
{
j--;
}
if (i < j)
{
temp = list[i];
list[i] = list[j];
list[j] = temp;
}
}
temp = list[j];
list[j] = list[pivot];
list[pivot] = temp;
quicksort(list, low, j - 1);
quicksort(list, j + 1, high);
}
}
