Interview Question Detect Capital

By Fatih KABAKCI

The problem is to detect the correct using of capitals in regard to the rules which have been exposed in the following.

Problem #520 - Detect Capital

Description: Given a word, you need to judge whether the usage of capitals in it is right or not.

We define the usage of capitals in a word to be right when one of the following cases holds:

1. All letters in this word are capitals, like "USA".
2. All letters in this word are not capitals, like "leetcode".
3. Only the first letter in this word is capital if it has more than one letter, like "Google".

Otherwise, we define that this word doesn not use capitals in a right way.

Example 1:
Input: "USA"
Output: True

Example 2:
Input: "FlaG"
Output: False

Note: The input will be a non-empty word consisting of uppercase and lowercase latin letters.

Difficulty: Easy

Solution in Java

package com.fatihkabakci.Easy.DetectCapital;

/**
 * @author fkabakci 
 * Problem Description: Given a word, you need to judge whether the usage of capitals in it is right or not.
 * 
 * We define the usage of capitals in a word to be right when one of the following cases holds:
 * 
 * 		1. All letters in this word are capitals, like "USA".
 * 		2. All letters in this word are not capitals, like "leetcode".
 * 		3. Only the first letter in this word is capital if it has more than one letter, like "Google".
 * 
 * Otherwise, we define that this word does not use capitals in a right way.
 * 
 * Example 1:
 * Input: "USA"
 * Output: True
 * 
 * Example 2:
 * Input: "FlaG"
 * Output: False
 * 
 * Note: The input will be a non-empty word consisting of uppercase and lowercase latin letters.
 * 
 * Solution:
 * 1. Check it out if all letters are capitals.
 * 2. Check it out if all letters are not capitals.
 * 3. Check it out if word is type of camel format.
 * 4. Return combined result with shaped OR logic.
 */
public class Solution {
	public boolean detectCapitalUse(String word) {
		int length = word.length();
		
		boolean isAllUpper = true;
        for(int i = 0; i < length && isAllUpper == true; i++)
        	if(Character.isLowerCase(word.charAt(i)))
        		isAllUpper = false;
        
        boolean isAllLower = true;
        for(int i = 0; i < length && isAllLower == true; i++)
        	if(Character.isUpperCase(word.charAt(i)))
        		isAllLower = false;
        
        boolean isCamelNotation = Character.isUpperCase(word.charAt(0));
        for(int i = 1; i < length && isCamelNotation == true; i++)
        	if(Character.isUpperCase(word.charAt(i)))
        		isCamelNotation = false;
        
        return isAllUpper || isAllLower || isCamelNotation;
    }

	public static void main(String[] args) {
		Solution s = new Solution();
		System.out.println(s.detectCapitalUse("Leetcode"));
	}
}