LeetCode Entry

290. Word Pattern

1.01.2023 easy 2023 kotlin

fun wordPattern(pattern: String, s: String): Boolean {

290. Word Pattern easy

https://t.me/leetcode_daily_unstoppable/71

blog post

    fun wordPattern(pattern: String, s: String): Boolean {
        val charToWord = Array<String>(27) { "" }
        val words = s.split(" ")
        if (words.size != pattern.length) return false
        words.forEachIndexed { i, w ->
            val cInd = pattern[i].toInt() - 'a'.toInt()

            if (charToWord[cInd] == "") {
                charToWord[cInd] = w
            } else if (charToWord[cInd] != w) return false
        }
        charToWord.sort()
        for (i in 1..26)
            if (charToWord[i] != "" && charToWord[i] == charToWord[i-1])
                return false
        return true
    }

Each word must be in 1 to 1 relation with each character in the pattern. We can check this rule.

Use string[27] array for char -> word relation and also check each char have a unique word assigned.

• don’t forget to check lengths

Space: O(N), Time: O(N)