Notes

BHAHHHHHHHHggggggggggg














#include<stdio.h>
#include<time.h>




void swap(int* a, int* b)
{
int t = *a;
*a = *b;
*b = t;
}




int partition2 (int arr[], int low, int high)
{
int pivot = arr[high]; // pivot
int i = (low - 1); // Index of smaller element

for (int j = low; j <= high- 1; j++)
{
// If current element is smaller than or
// equal to pivot
if (arr[j] >= pivot)
{
i++; // increment index of smaller element
swap(&arr[i], &arr[j]);
}
}
swap(&arr[i + 1], &arr[high]);
return (i + 1);
}

void quickSortdesc(int arr[], int low, int high)
{
if (low < high)
{
/* pi is partitioning index, arr[p] is now
at right place */
int pi = partition2(arr, low, high);

// Separately sort elements before
// partition and after partition
quickSortdesc(arr, low, pi - 1);
quickSortdesc(arr, pi + 1, high);
}
}







int partition (int arr[], int low, int high)
{
int pivot = arr[high]; // pivot
int i = (low - 1); // Index of smaller element

for (int j = low; j <= high- 1; j++)
{
// If current element is smaller than or
// equal to pivot
if (arr[j] <= pivot)
{
i++; // increment index of smaller element
swap(&arr[i], &arr[j]);
}
}
swap(&arr[i + 1], &arr[high]);
return (i + 1);
}

/* The main function that implements QuickSort
arr[] --> Array to be sorted,
low --> Starting index,
high --> Ending index */
void quickSort(int arr[], int low, int high)
{
if (low < high)
{
/* pi is partitioning index, arr[p] is now
at right place */
int pi = partition(arr, low, high);

// Separately sort elements before
// partition and after partition
quickSort(arr, low, pi - 1);
quickSort(arr, pi + 1, high);
}
}

/* Function to print an array */
void printArray(int arr[], int size)
{
int i;
for (i=0; i < size; i++)
printf("%d ", arr[i]);
printf("n");
}

// Driver program to test above functions
int main(void)
{

clock_t start,end;
double CPU_time;
start = clock();
int arr[] = {10, 7, 8, 9, 1, 5};
int n = sizeof(arr)/sizeof(arr[0]);


{ int d;
printf("ntArray generatednt1. Sort array in ascnt2. Sort array in descnt3. Best Casent4. Worst Casent5. Average Casent6. Quitnt ");
scanf("%d",&d);
while(d!=6 || d>=1)
{
switch(d){

case 1: quickSort(arr, 0, n-1);
break;
case 2: quickSortdesc(arr, 0, n-1);
break;
case 3: quickSort(arr, 0, n-1);
quickSort(arr, 0, n-1);
break;
case 4: quickSortdesc(arr, 0, n-1);
quickSort(arr, 0, n-1);
break;
case 5: quickSort(arr, 0, n-1);
break;
case 6: break;
default: printf("wrong choixce");
}
}
}





printf("ntSorted array: ");
printArray(arr, n);
end=clock();
CPU_time=((double)(end-start))/CLOCKS_PER_SEC;
printf("n quick sort took %f seconds to execute n",CPU_time);
return 0;
}