Question.md

Question: Capital Usage Validator

Difficulty Level: 🟢 Beginner
Domain: String Processing (Validation)

Objective:

Given a word, determine if its capitalization is used correctly. We define correct capitalization as follows:

1. All letters in the word are uppercase (e.g., "USA").
2. All letters in the word are lowercase (e.g., "leetcode").
3. Only the first letter in the word is uppercase (e.g., "Google").

If any of these conditions are met, return True. Otherwise, return False.

Conceptual Background:

To validate correct capitalization, we simply need to check three conditions for the input word:

1. All Uppercase: Every letter in the word is capital.
2. All Lowercase: Every letter in the word is lowercase.
3. Title Case: Only the first letter is uppercase, and all other letters are lowercase.

Python provides straightforward string methods (isupper, islower, and istitle) to evaluate each of these cases, allowing for an efficient solution.

Example Execution:

• Input: "USA"

• Processing:

  • isupper() returns True because all letters are uppercase.
  • Since one condition is satisfied, the function returns True.

• Output: True

• Input: "Google"

• Processing:

  • istitle() returns True since only the first letter is uppercase.
  • The function returns True.

• Output: True

• Input: "flaG"

• Processing:

  • None of the conditions (isupper, islower, istitle) are satisfied.
  • The function returns False.

• Output: False