#84 48 13 20 61 20 33 97 34 45 6 63 71 66 24 57 92 74 6 25 51 86 48 15 64 55 77 30 56 53 37 99 9 59 57 61 30 97 50 63 59 62 39 32 34 4 96 51 8 86 10 62 16 55 81 88 71 25 27 78 79 88 92 50 16 8 67 82 67 37 84 3 33 4 78 98 39 64 98 94 24 82 45 3 53 74 96 9 10 94 13 79 15 27 56 66 32 81 77
# xor a list of integers to find the lonely integer
res = a[0]
    for i in range(1,len(a)):
        res = res ^ a[i]

class Solution(object):
    def floodFill(self, image, sr, sc, newColor):
        R, C = len(image), len(image[0])
        color = image[sr][sc]
        if color == newColor: return image
        def dfs(r, c):
            if image[r][c] == color:
                image[r][c] = newColor
                if r >= 1: dfs(r-1, c)
                if r+1 < R: dfs(r+1, c)
                if c >= 1: dfs(r, c-1)
                if c+1 < C: dfs(r, c+1)

        dfs(sr, sc)
        return image

import random

class Node:

    def __init__(self, c):

        self.left = None
        self.right = None
        self.color = c
    
    def SetColor(self,c) :
        self.color = c

    def PrintNode(self) :
        print(self.color)

def insert(s, root, i, n):
    if i < n:
        temp = Node(s[i]) 
        root = temp 
        root.left = insert(s, root.left,2 * i + 1, n) 
        root.right = insert(s, root.right,2 * i + 2, n)
    return root
  

def MakeTree(s) :
    list = insert(s,None,0,len(s))
    return list


def MakeSet() :
    s = []
    count = random.randint(7,12)
    for _ in range(count) :
        color = random.randint(0,1) == 0 and "Red" or "White"
        s.append(color)
    return s

def ChangeColor(root) :
    if (root != None) :
        if (root.color == "White") :
            root.SetColor("Red")
        ChangeColor(root.left)
        ChangeColor(root.right)


def PrintList(root) :
    if root.left != None :
        PrintList(root.left)
    else :
        root.PrintNode()
    if root.right != None :
        PrintList(root.right)
    else :
        root.PrintNode()


t1 = MakeTree(MakeSet())
print("Original Colors For Tree 1:\n")
PrintList(t1)
ChangeColor(t1)
print("New Colors For Tree 1:\n")
PrintList(t1)

t2 = MakeTree(MakeSet())
print("Original Colors For Tree 2:\n")
PrintList(t2)
ChangeColor(t2)
print("New Colors For Tree 2:\n")
PrintList(t2)

t3 = MakeTree(MakeSet())
print("Original Colors For Tree 3:\n")
PrintList(t3)
ChangeColor(t3)
print("New Colors For Tree 3:\n")
PrintList(t3)

my_list = [1, 2, 3, 4, 5]
removed_element = my_list.pop(2)  # Remove and return element at index 2
print(removed_element)  # 3
print(my_list)  # [1, 2, 4, 5]

last_element = my_list.pop()  # Remove and return the last element
print(last_element)  # 5
print(my_list)  # [1, 2, 4]

x[cat_var].isnull().sum().sort_values(ascending=False)

# @return a list of strings, [s1, s2]
def letterCombinations(self, digits):
    if '' == digits: return []
    kvmaps = {
        '2': 'abc',
        '3': 'def',
        '4': 'ghi',
        '5': 'jkl',
        '6': 'mno',
        '7': 'pqrs',
        '8': 'tuv',
        '9': 'wxyz'
    }
    return reduce(lambda acc, digit: [x + y for x in acc for y in kvmaps[digit]], digits, [''])