Quick Sort With Pivot At Random Element

 # Q.14 Write A Python Program To Store First Year Percentage Of Students In Array.

#      Write Function For Sorting Array Of Floating Point Numbers In Ascending Order Using Quick
#      Sort And Display Top Five Scores


# Quick Sort

import random

def partition(arr, left, right):

    randint = random.randint(left, right)
    arr[randint], arr[right] = arr[right], arr[randint]
    pivot = arr[right]
    first = left
    last = right - 1

    while True:

        while first <= last and arr[first] <= pivot:
            first = first + 1

        while first <= last and arr[last] >= pivot:
            last = last - 1

        if first < last:
            arr[first], arr[last] = arr[last], arr[first]

        else:
            break

    arr[right], arr[first] = arr[first], arr[right]
    return first


def quickSort(arr, left, right):

    if left < right:
        pivotindex = partition(arr, left, right)
        quickSort(arr, left, pivotindex - 1)
        quickSort(arr, pivotindex + 1, right)

    return arr


if __name__ == '__main__':

    try:
        num = int(input("Enter The Number Of Students\n"))
        arr = []

        for i in range(num):
            userinput = int(
                input(f"Enter The Percentage Of Student {i + 1}\n"))
            arr.append(userinput)

        print("\nUnsorted Array =", arr)

        low = 0
        high = num - 1

        print("Sorted Array =", quickSort(arr, low, high))

        print("\nTop Five Scores Are : ")

        maxarr = []
        i = 0

        while i < num:

            i = i + 1
            if arr[-i] == arr[-i + 1]:
                continue

            maxarr.append(arr[-i])

            if len(maxarr) == 5:
                break

        for i in range(len(maxarr)):
            print(maxarr[i], "%")

    except Exception as e:
        print("Wrong Input, Please Enter Integers Only!!")


# Output

# Enter The Number Of Students
# 10

# Enter The Percentage Of Student 1
# 84
# Enter The Percentage Of Student 2
# 84
# Enter The Percentage Of Student 3
# 85
# Enter The Percentage Of Student 4
# 78
# Enter The Percentage Of Student 5
# 75
# Enter The Percentage Of Student 6
# 68
# Enter The Percentage Of Student 7
# 65
# Enter The Percentage Of Student 8
# 88
# Enter The Percentage Of Student 9
# 89
# Enter The Percentage Of Student 10
# 92

# Unsorted Array = [84, 84, 85, 78, 75, 68, 65, 88, 89, 92]
# Sorted Array = [65, 68, 75, 78, 84, 84, 85, 88, 89, 92]

# Top Five Scores Are :
# 92 %
# 89 %
# 88 %
# 85 %
# 84 %