Search⌘ K
AI Features
Home
Courses
Grokking the Coding Interview Patterns in Python

Lexicographical Numbers

Explore how to generate all numbers from 1 to n in lexicographical order using trie patterns. Understand the problem constraints, develop your own solution, and optimize for O(n) time and space complexity through hands-on implementation.

We'll cover the following...

Statement

Given an integer value nn, write a function that returns all the numbers in the range 11 to nn in lexicographical orderLexicographical order, also known as dictionary order or alphabetical order, is a way of ordering sequences (such as strings) based on the order of their elements. .

Constraints:

  • 1≤n≤1031 \leq n \leq 10^3

Examples

Understand the problem

Let’s take a moment to make sure you’ve correctly understood the problem. The quiz below helps you check if you’re solving the correct problem:

Lexicographical Numbers

1.

Which lexicographical order is correct for the given number?

n = 7

A.

[1, 2, 3, 4, 5, 6]

B.

[1, 2, 3, 4, 5, 6, 7]

C.

[0, 1, 2, 3, 4, 5, 6, 7]

D.

[0, 1, 2, 3, 4, 5, 6]

1 / 3

Figure it out!

We have a game for you to play. Rearrange the logical building blocks to develop a clearer understanding of how to solve this problem.

Note: As an additional challenge, we have intentionally hidden the solution to this puzzle.

Sequence - Vertical
Drag and drop the cards to rearrange them in the correct sequence.
1
2
3

Try it yourself

Implement your solution in main.py in the following coding playground. We have provided useful code templates in the other files that you may build on to solve this problem.

We have left the solution to this challenge as an exercise for you. The optimal solution to this problem runs in O(n) time and takes O(n) space. You may try to translate the logic of the solved puzzle into a coded solution.

Python
usercode > main.py
def lexicographical_order(n):



    # Replace this placeholder return statement with your code

    return []
Lexicographical Numbers