Keyboard Row

Given an array of strings words, return the words that can be typed using letters of the alphabet on only one row of American keyboard. Source

package questions


import _utils.UseCommentAsDocumentation
import utils.shouldBe

/**
 * Given an array of strings words, return the words that can be typed
 * using letters of the alphabet on only one row of American keyboard.
 * [Source](https://leetcode.com/problems/keyboard-row/)
 */
@UseCommentAsDocumentation
private fun findWords(words: Array<String>): Array<String> {
    val result = ArrayList<String>(words.size)
    val rows = arrayOf("qwertyuiop", "asdfghjkl", "zxcvbnm")
    val charIndexMap = HashMap<Char, Int>(26)
    rows.forEachIndexed { index, str ->
        str.toCharArray().forEach {
            charIndexMap[it] = index
        }
    }
    words.forEach {
        if (it.toCharArray().map { char -> charIndexMap[char.toLowerCase()] }.distinct().size == 1) {
            result.add(it)
        }
    }
    return result.toTypedArray()
}

fun main() {
    findWords(arrayOf("Hello", "Alaska", "Dad", "Peace")) shouldBe arrayOf("Alaska", "Dad")
    findWords(arrayOf("omk")) shouldBe arrayOf()
    findWords(arrayOf("adsdf", "sfd")) shouldBe arrayOf("adsdf", "sfd")
}

---

View on GitHub

Updated on 2021-10-23