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

Solution: Integer to English Words

Explore how to convert a nonnegative integer into its English word representation in C++. Learn to break down numbers by digits and positional values, and build a scalable solution that covers ranges from zero to billions. Understand the algorithm's structure and complexity to effectively implement this common coding interview problem.

We'll cover the following...

Statement

Given a nonnegative integer, num, convert it to its English word representation.

Constraints:

  • 0≤0 \le num ≤231−1\le 2^{31}-1

Solution

To solve this problem, we need to understand the different types of words that can appear in the word representation of a number, which depend on three factors:

  1. Digits: There are ten digits ranging from 0 to 9.

  2. Number of digits: In our case, the maximum number of digits could be 1010 because the input number, num, will be in the range [0, 2147483647].

  3. Positional values: The positional value, also known as place value, of a digit can be ones (units), tens, hundreds, thousands, ten thousands, hundred thousands, millions, ten millions, hundred millions, or billions.

Based on these factors, numbers in different ranges have specific word representations. Here’s a general workflow for converting numbers to their word representation:

  1. Numbers from 00 ...