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):
#coding: UTF-8

import copy
class Algo:
  @staticmethod
  def bubbleSort(r, c, n):
    print(r)
    print(c)
    tmp_r, tmp_c = r, c
    flag = 1
    while flag:
      flag = 0
      for j in range(n-1, 0, -1):
        if tmp_c[j] < tmp_c[j-1]:
          tmp_c[j], tmp_c[j-1] = tmp_c[j-1], tmp_c[j]
          tmp_r[j], tmp_r[j-1] = tmp_r[j-1], tmp_r[j]
          flag = 1
    return tmp_r

  def selectionSort(r, c, n):
    print(r)
    print(c)
    tmp_r, tmp_c = r, c
    for i in range(0,n):
      minj = i
      for j in range(i,n):
        if tmp_c[j] < tmp_c[minj]:
          minj = j
      if tmp_c[i] != tmp_c[minj]:
        tmp_c[i], tmp_c[minj] = tmp_c[minj], tmp_c[i]
        tmp_r[j], tmp_r[minj] = tmp_r[minj], tmp_r[j]
    return tmp_r

  def createIntList(r, n):
    c = []
    for i in range(0,n):
      c.append(r[i][1])
    return c

  def printList(r, n):
    for i in range(0,n):
      if i == n-1:
        print(r[i])
      else:
        print(r[i], " ", sep="", end="")

n = int(input())
r = list(map(str,input().split()))
c = Algo.createIntList(r, n)
br = Algo.bubbleSort(copy.deepcopy(r), copy.deepcopy(c), n)
ir = Algo.selectionSort(copy.deepcopy(r), copy.deepcopy(c), n)
Algo.printList(br, n)
print("Stable")
Algo.printList(ir, n)
if br == ir:
  print("Stable")
else:
  print("Not stable")

Fixed, accepted submission:
#coding: UTF-8

import copy
class Algo:
  @staticmethod
  def bubbleSort(r, c, n):
    flag = 1
    while flag:
      flag = 0
      for j in range(n-1, 0, -1):
        if c[j] < c[j-1]:
          c[j], c[j-1] = c[j-1], c[j]
          r[j], r[j-1] = r[j-1], r[j]
          flag = 1
    return r

  def selectionSort(r, c, n):
    for i in range(0,n):
      minj = i
      for j in range(i,n):
        if c[j] < c[minj]:
          minj = j
      if c[i] != c[minj]:
        c[i], c[minj] = c[minj], c[i]
        r[i], r[minj] = r[minj], r[i]
    return r

  def createIntList(r, n):
    c = []
    for i in range(0,n):
      c.append(r[i][1])
    return c

  def printList(r, n):
    for i in range(0,n):
      if i == n-1:
        print(r[i])
      else:
        print(r[i], " ", sep="", end="")

n = int(input())
r = list(map(str,input().split()))
c = Algo.createIntList(r, n)
br = Algo.bubbleSort(copy.deepcopy(r), copy.deepcopy(c), n)
ir = Algo.selectionSort(copy.deepcopy(r), copy.deepcopy(c), n)
Algo.printList(br, n)
print("Stable")
Algo.printList(ir, n)
if br == ir:
  print("Stable")
else:
  print("Not stable")