Problem:
Let's arrange a deck of cards. There are totally 36 cards of 4 suits(S, H, C, D) and 9 values (1, 2, ... 9). For example, 'eight of heart' is represented by H8 and 'one of diamonds' is represented by D1.  Your task is to write a program which sorts a given set of cards in ascending order by their values using the Bubble Sort algorithms and the Selection Sort algorithm respectively. These algorithms should be based on the following pseudocode:                 BubbleSort(C) 1 for i = 0 to C.length-1 2     for j = C.length-1 downto i+1 3         if C[j].value < C[j-1].value 4             swap C[j] and C[j-1]                 SelectionSort(C) 1 for i = 0 to C.length-1 2     mini = i 3     for j = i to C.length-1 4         if C[j].value < C[mini].value 5             mini = j 6     swap C[i] and C[mini]   Note that, indices for array elements are based on 0-origin.  For each algorithm, report the stability of the output for the given input (instance). Here, 'stability of the output' means that: cards with the same value appear in the output in the same order as they do in the input (instance).

Incorrect submission (verdict: Wrong Answer):
#!/usr/bin/env python3
# -*- coding: utf-8 -*-


class Card(object):

    def __init__(self, card):
        self.card = card
        self.suit = card[0]
        self.value = int(card[1:])

    def __str__(self):
        return str(self.card)


def print_array(a):
    print(" ".join(map(str, a)))


def bubblesort(cards, n):
    c = cards[:]
    for i in range(0, n):
        for j in range(n - 1, i - 1, -1):
            if c[j].value < c[j - 1].value:
                (c[j], c[j - 1]) = (c[j - 1], c[j])
    return c


def selectionsort(cards, n):
    c = cards[:]
    for i in range(0, n):
        minj = i
        for j in range(i, n):
            if c[j].value < c[minj].value:
                minj = j
        (c[i], c[minj]) = (c[minj], c[i])
    return c


def main():
    n = int(input())
    cards = list(map(Card, input().split()))
    b = bubblesort(cards, n)
    print_array(b)
    print("Stable")
    s = selectionsort(cards, n)
    print_array(s)
    if b == s:
        print("Stable")
    else:
        print("Not Stable")


if __name__ == "__main__":
    main()

Fixed, accepted submission:
#!/usr/bin/env python3
# -*- coding: utf-8 -*-


class Card(object):

    def __init__(self, card):
        self.card = card
        self.suit = card[0]
        self.value = int(card[1:])

    def __str__(self):
        return str(self.card)


def print_array(a):
    print(" ".join(map(str, a)))


def bubblesort(cards, n):
    c = cards[::]
    for i in range(0, n):
        for j in range(n - 1, i, -1):
            if c[j].value < c[j - 1].value:
                (c[j], c[j - 1]) = (c[j - 1], c[j])
    return c


def selectionsort(cards, n):
    c = cards[::]
    for i in range(0, n):
        minj = i
        for j in range(i, n):
            if c[j].value < c[minj].value:
                minj = j
        (c[i], c[minj]) = (c[minj], c[i])
    return c


def main():
    n = int(input())
    cards = list(map(Card, input().split()))
    b = bubblesort(cards, n)
    print_array(b)
    print("Stable")
    s = selectionsort(cards, n)
    print_array(s)
    if b == s:
        print("Stable")
    else:
        print("Not stable")


if __name__ == "__main__":
    main()