Problem

Given a List of words, return the words that can be typed using letters of alphabet on only one row’s of American keyboard.

Example:

Input: [“Hello”, “Alaska”, “Dad”, “Peace”]

Output: [“Alaska”, “Dad”]

Note:

You may use one character in the keyboard more than once.

You may assume the input string will only contain letters of alphabet.

Pre analysis

Will keep a hashmap of alphabet in keyboard corresponding to row number, if all characters in words are from same row then it is our candidate else no.

Another Solution

Different code for same approach

var findWords = function(words) {
    const top = "qwertyuoip".split('');
    const mid = "asdfghjkl".split('');
    const bot = "zxcvbnm".split('');

    return words.filter((w) => {
        const ws = w.toLowerCase().split('');
        const a = ws.find(l => top.indexOf(l) === -1);
        const b = ws.find(l => mid.indexOf(l) === -1);
        const c = ws.find(l => bot.indexOf(l) === -1);
        return !a || !b || !c;
    });
};