LeetCode Entry

Reverse Words In A String

13.11.2022 medium 2022 kotlin

A simple trick: reverse all the string, then reverse each word.

https://leetcode.com/problems/reverse-words-in-a-string/ medium

A simple trick: reverse all the string, then reverse each word.

    fun reverseWords(s: String): String {
        val res = StringBuilder()
        val curr = Stack<Char>()
        (s.lastIndex downTo 0).forEach { i ->
            val c = s[i]
            if (c in '0'..'z') curr.push(c)
            else if (curr.isNotEmpty()) {
                if (res.length > 0) res.append(' ')
                while (curr.isNotEmpty()) res.append(curr.pop())
            }
        }
        if (curr.isNotEmpty() && res.length > 0) res.append(' ')
        while (curr.isNotEmpty()) res.append(curr.pop())
        return res.toString()
    }

Complexity: O(N) Memory: O(N) - there is no O(1) solution for string in JVM