List Comprehensions in Python HackerRank Solution

Hello Programmers, In this post, you will know how to solve the List Comprehensions in Python HackerRank Solution. This problem is a part of the HackerRank Python Programming Series.

One more thing to add, don’t directly look for the solutions, first try to solve the problems of Hackerrank by yourself. If you find any difficulty after trying several times, then you can look for solutions.

List Comprehensions in Python HackerRank Solution

problem

Let’s learn about list comprehensions! You are given three integers X,Y and Z representing the dimensions of a cuboid along with an integer N. You have to print a list of all possible coordinates given by (i,j,k) on a 3D grid where the sum of i+j+k is not equal to N. Here, 0<=i<=X; 0<=j<=Y; 0<=k<=Z

Example

x = 1

y = 1

z = 2

n = 3

Input Format

Four integers x, y, z and n, each on a separate line.

Constraints

Print the list in lexicographic increasing order.

Sample Input 0

1
1
1
2

Sample Output 0

[[0, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0], [1, 1, 1]]

Explanation 0

Concept

You have already used lists in previous hacks. List comprehensions are an elegant way to build a list without having to use different for loops to append values one by one. This example might help.

Example: You are given two integers x and y . You need to find out the ordered pairs ( i , j ) , such that ( i + j ) is not equal to n and print them in lexicographic order.( 0 <= i <= x ) and ( 0 <= j <= y) This is the code if we dont use list comprehensions in Python.

python x = int ( raw_input()) y = int ( raw_input()) n = int ( raw_input()) ar = [] p = 0 for i in range ( x + 1 ) : for j in range( y + 1): if i+j != n: ar.append([]) ar[p] = [ i , j ] p+=1 print ar
Other smaller codes may also exist, but using list comprehensions is always a good option. Code using list comprehensions:

python x = int ( raw_input()) y = int ( raw_input()) n = int ( raw_input()) print [ [ i, j] for i in range( x + 1) for j in range( y + 1) if ( ( i + j ) != n )]

Sample Input 1

2
2
2
2

Sample Output 1

[[0, 0, 0], [0, 0, 1], [0, 1, 0], [0, 1, 2], [0, 2, 1], [0, 2, 2], [1, 0, 0], [1, 0, 2], [1, 1, 1], [1, 1, 2], [1, 2, 0], [1, 2, 1], [1, 2, 2], [2, 0, 1], [2, 0, 2], [2, 1, 0], [2, 1, 1], [2, 1, 2], [2, 2, 0], [2, 2, 1], [2, 2, 2]]

List Comprehensions in Python Hacker Rank Solution

if __name__ == '__main__':
    x = int(input())
    y = int(input())
    z = int(input())
    n = int(input())
    print(list([i,j,k] for i in range(x+1) for j in range(y+1) for k in range(z+1)  if i+j+k !=n))

Disclaimer: The above Problem (List Comprehensions in Python) is generated by Hackerrank but the Solution is Provided by BrokenProgrammers. This tutorial is only for Educational and Learning purposes.

Next: Nested Lists in Python HackerRank Solution