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):
def bubble_sort(n, key=0):
    c = 0
    r = [x if isinstance(x, list) else [x] for x in n[:]]
    l = len(r) - 1
    for i in range(0, l):
        for j in range(l, i, -1):
            if r[j][key] < r[j-1][key]:
                r[j], r[j-1] = r[j-1], r[j]
                c += 1
    r = [x[0] if len(x) == 1 else x for x in r]
    return {'list': r, 'count': c}

def selection_sort(n, key=0):
    c = 0
    r = [x if isinstance(x, list) else [x] for x in n[:]]
    l = len(r)
    for i in range(0, l):
        mini = i
        for j in range(i, l):
            if (r[j][key] < r[mini][key]):
                mini = j
        if mini != i:
            r[i], r[mini] = r[mini], r[i]
            c += 1
    r = [x[0] if len(x) == 1 else x for x in r]
    return {'list': r, 'count': c}

def card_format(cards):
    return ' '.join([x[0] + str(x[1]) for x in cards])

if __name__ == '__main__':
    n = int(input())
    c = list(map(list, input().split(' ')))
    c = [[x[0], int(x[1])] for x in c]
    bsc = card_format(bubble_sort(c, 1)['list'])
    ssc = card_format(selection_sort(c, 1)['list'])
    print(bsc)
    print('Stable')
    print(ssc)
    print('Stable' if bsc == ssc else 'Unstable')



Fixed, accepted submission:
def bubble_sort(n, key=0):
    c = 0
    r = [x if isinstance(x, list) else [x] for x in n[:]]
    l = len(r) - 1
    for i in range(0, l):
        for j in range(l, i, -1):
            if r[j][key] < r[j-1][key]:
                r[j], r[j-1] = r[j-1], r[j]
                c += 1
    r = [x[0] if len(x) == 1 else x for x in r]
    return {'list': r, 'count': c}

def selection_sort(n, key=0):
    c = 0
    r = [x if isinstance(x, list) else [x] for x in n[:]]
    l = len(r)
    for i in range(0, l):
        mini = i
        for j in range(i, l):
            if (r[j][key] < r[mini][key]):
                mini = j
        if mini != i:
            r[i], r[mini] = r[mini], r[i]
            c += 1
    r = [x[0] if len(x) == 1 else x for x in r]
    return {'list': r, 'count': c}

def card_format(cards):
    return ' '.join([x[0] + str(x[1]) for x in cards])

if __name__ == '__main__':
    n = int(input())
    c = list(map(list, input().split(' ')))
    c = [[x[0], int(x[1])] for x in c]
    bsc = card_format(bubble_sort(c, 1)['list'])
    ssc = card_format(selection_sort(c, 1)['list'])
    print(bsc)
    print('Stable')
    print(ssc)
    print('Stable' if bsc == ssc else 'Not stable')