Day 20: Sorting - Hacker Rank Solution (Python) Code

Objective
Today, we're discussing a simple sorting algorithm called Bubble Sort. Check out the Tutorial tab for learning materials and an instructional video!

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Consider the following version of Bubble Sort:

for (int i = 0; i < n; i++) {
    // Track number of elements swapped during a single array traversal
    int numberOfSwaps = 0;
    
    for (int j = 0; j < n - 1; j++) {
        // Swap adjacent elements if they are in decreasing order
        if (a[j] > a[j + 1]) {
            swap(a[j], a[j + 1]);
            numberOfSwaps++;
        }
    }
    
    // If no elements were swapped during a traversal, array is sorted
    if (numberOfSwaps == 0) {
        break;
    }
}

Task
Given an array, , of size  distinct elements, sort the array in ascending order using the Bubble Sort algorithm above. Once sorted, print the following  lines:

1. Array is sorted in numSwaps swaps.
   where  is the number of swaps that took place.
2. First Element: firstElement
   where  is the first element in the sorted array.
3. Last Element: lastElement
   where  is the last element in the sorted array.

Hint: To complete this challenge, you will need to add a variable that keeps a running tally of all swaps that occur during execution.

Input Format

The first line contains an integer, , denoting the number of elements in array .
The second line contains  space-separated integers describing the respective values of .

Constraints

• , where .

Output Format

Print the following three lines of output:

1. Array is sorted in numSwaps swaps.
   where  is the number of swaps that took place.
2. First Element: firstElement
   where  is the first element in the sorted array.
3. Last Element: lastElement
   where  is the last element in the sorted array.

Sample Input 0

3
1 2 3

Sample Output 0

Array is sorted in 0 swaps.
First Element: 1
Last Element: 3

Explanation 0

The array is already sorted, so  swaps take place and we print the necessary  lines of output shown above.

Sample Input 1

3
3 2 1

Sample Output 1

Array is sorted in 3 swaps.
First Element: 1
Last Element: 3

Explanation 1

The array  is not sorted, so we perform the following  swaps:

At this point the array is sorted and we print the necessary  lines of output shown above.

#!/bin/python3
import sys

n = int(input().strip())
a = list(map(int, input().strip().split(' ')))
# Write Your Code Here
count = 0
for i in range(len(a)-1):
    for j in range(0,len(a)-1):
        if a[j] > a[j+1]:
            a[j], a[j+1] = a[j+1], a[j]
            count += 1
print('Array is sorted in {} swaps.'.format(count))
print('First Element: {}'.format(a[0]))
print('Last Element: {}'.format(a[-1]))