Development Interview Questions (Python)

Dynamic Programming

Check if any valid sequence is divisible by M
Given an array of N integers, using ‘+’ and ‘-‘ between the elements check if there is a  way to form a sequence of numbers which evaluate to a number divisible by M 
Examples: 
Input: arr = {1, 2, 3, 4, 6}       
M = 4
Output: True, 
There is a valid sequence i. e., (1 - 2  + 3 + 4 + 6), which evaluates to 12 that  is divisible by 4   

Input: arr = {1, 3, 9}       
M = 2
Output: False
There is no sequence which evaluates to  a number divisible by M.

Answer (in Python):

def check_if_any_valid_sequence_is_divisible(my_list, my_num):
    if len(my_list) == 0:
        return print("False")
    elif len(my_list) == 1:
        #print(my_list[0] // my_num)        #print(my_list[0] % my_num)        if my_list[0] == 0:
            return print("False")
        else:
            if ((my_list[0] % my_num) == 0) and ((my_list[0] // my_num) == 1):
                return print("True")
            else:
                return print("False")
    elif len(my_list) > 1:
        temp = False        for data in my_list:
            if data != 0:
                # print(data // my_num)                # print(data % my_num)                if ((data % my_num) == 0) and ((data // my_num) == 1):
                    temp = True        return print(temp)


def create_all_sequence(my_list, my_num):
    if len(my_list) == 0:
        return print("False")
    elif len(my_list) == 1:
        check_if_any_valid_sequence_is_divisible(my_list, my_num)
    elif len(my_list) > 1:
        previous = None        temp_list = []
        for data in my_list:
            if not previous:
                previous = data
            else:
                if not temp_list:
                    temp_list.append(previous + data)
                    temp_list.append(previous - data)
                else:
                    #print(temp_list)                    temp_list1 = []
                    for info in temp_list:
                        temp_list1.append(info + data)
                        temp_list1.append(info - data)
                    temp_list = temp_list1
        #print(temp_list)        check_if_any_valid_sequence_is_divisible(temp_list, my_num)


m = 4arr = []
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [4]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 2]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 3]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 2, 3]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 2, 3, 4]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 2, 4, 7, 9]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

arr = [1, 2, 3, 4, 6]
print("Check if any valid sequence in " + str(arr) + " is divisible by " + str(m))
create_all_sequence(arr, m)

Arrays & String manipulation (palindrome)    

Given a string, calculate and print all its possible palindromic partitions. ​(A palindrome is  a word, phrase, or sequence that reads the same backwards as forwards) 
Examples:   
Input: nitin
Output:
n i t i n           
n iti n           
nitin 

Input: geeks
Output:
g e e k s           
g ee k s

Answer (in Python):

def check_palindrome_str(given_str):
    # make string aggressive lower    given_str = given_str.casefold()
    # reverse string    reversed_str = reversed(given_str)
    #print(list(given_str))    #print(list(reversed_str))
    # compare strings    if list(given_str) == list(reversed_str):
        return True    else:
        return False

def palindrome_str(given_str):
    # set var    num_pali = 0    list_pali = []
    list_str = list(given_str)
    #print(given_str)    #print(list_str)
    # create all combinations of substrings    for letter1 in list_str:
        for letter2 in given_str:
            temp_str = letter1 + letter2
            if temp_str in given_str:
                if temp_str not in list_str:
                    list_str.append(temp_str)
                    #print(temp_str)    #print(list_str)
    # Loop thru words in list    for words in list_str:
        #print(words)        #print(check_palindrome_str(given_str))
        # check if word is palindrome        if check_palindrome_str(words):
            num_pali += 1            list_pali.append(words)

    print("'" + given_str + "' has " + str(num_pali) + " palindrome sub strings")
    if list_pali:
        for word in list_pali:
            print(word)


my_str = "nitin"palindrome_str(my_str)
my_str = "greeks"palindrome_str(my_str)
my_str = "racecar"palindrome_str(my_str)