Given the number of students in the class and their percentage as
achieved in the first year of their term as an input to the Python
program. you should Sort the percentage using a quick sort algorithm
in ascending order and at the end you have to print the top five
percentages.
As you are starting the percentage in ascending order in order to print the top five percent you have to print from the bottom.
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
Quicksort
algorithm is a divide and conquer algorithm that divides the given array
based on the pivot and then calls the quick sort algorithm recursively.
Until the complete array is sorted.
In the below Quicksort algorithm the pivot is picked as the start element of the list.
Take
a function named divide() and pass the input argument as the list
start and end index of the list. take a variable name the pivot and
assign the start element of the list take two indexes low and high.
def divide(my_list, start, end):
pivot = my_list[start]
low = start + 1
high = end
Using
the while loop iterate all the items from the end if you find the
element which is less than pivot move the high pointer to that position
Using
another while loop iterate all the items from the start of the list
and check if any item which is greater than the pivot move the low
pointer to it
Swap the lower and higher position values
At the end of the while loop swap the pivot position with the higher position and return the high index
while True:
while low <= high and my_list[high] >= pivot:
high = high - 1
while low <= high and my_list[low] <= pivot:
low = low + 1
if low <= high:
my_list[low], my_list[high] = my_list[high], my_list[low]
else:
break
my_list[start], my_list[high] = my_list[high], my_list[start]
return high
Use
another function named as quick_sort() function, pass the list,
start index and end index as argument. Divide the list by calling the
above function with the help of pivot positions. Call the Quicksort
function again recursively for both the list.
def quick_sort(my_list, start, end):
if start >= end:
return
d = divide(my_list, start, end)
quick_sort(my_list, start, d - 1)
quick_sort(my_list, d + 1, end)
In
the main program take a variable length and after user to enter the
number of students in the class. take an empty list of percentages and
use the for loop to iterate from 0 to list length and ask the user to
enter the percentage of each student.
length = int(input("Enter Number of Students in Class : "))
percentages = []
for index in range(length):
temp = float(input(f"Enter Student #{index} Percentage : "))
percentages.append(temp)
Print
a user friendly message and call the quick sort function. what is
the student percentage are sorted using the for loop and list slicing
technique get the last five percentages.
The last 5 percentages are the top 5 Percentage because you have sorted the array in ascending order(smallest to highest)
print("Top 5 Percentages of Students are ...")
quick_sort(percentages, 0, len(percentages) - 1)
for percentage in (percentages[::-1])[:5]:
print(percentage)
Complete Python program
========================
def divide(my_list, start, end):
pivot = my_list[start]
low = start + 1
high = end
while True:
while low <= high and my_list[high] >= pivot:
high = high - 1
while low <= high and my_list[low] <= pivot:
low = low + 1
if low <= high:
my_list[low], my_list[high] = my_list[high], my_list[low]
else:
break
my_list[start], my_list[high] = my_list[high], my_list[start]
return high
def quick_sort(my_list, start, end):
if start >= end:
return
d = divide(my_list, start, end)
quick_sort(my_list, start, d - 1)
quick_sort(my_list, d + 1, end)
length = int(input("Enter Number of Students in Class : "))
percentages = []
for index in range(length):
temp = float(input(f"Enter Student #{index} Percentage : "))
percentages.append(temp)
print("Top 5 Percentages of Students are ...")
quick_sort(percentages, 0, len(percentages) - 1)
for percentage in (percentages[::-1])[:5]:
print(percentage)
OUTPUT
=================
Enter Number of Students in Class : 10
Enter Student #0 Percentage : 99
Enter Student #1 Percentage : 90
Enter Student #2 Percentage : 80
Enter Student #3 Percentage : 76
Enter Student #4 Percentage : 75
Enter Student #5 Percentage : 74
Enter Student #6 Percentage : 73
Enter Student #7 Percentage : 72
Enter Student #8 Percentage : 71
Enter Student #9 Percentage : 50
Top 5 Percentages of Students are ...
99.0
90.0
80.0
76.0
75.0
Conclusion
====================
Comment down below if you have any suggestions to improve the above Python program.
0 Comments