[LeetCode/Kotlin]344. Reverse String

344. Reverse String (Kotlin)

 

문제

Write a function that reverses a string. The input string is given as an array of characters s.

You must do this by modifying the input array in-place with O(1) extra memory.

Example 1:

Input: s = ["h","e","l","l","o"]
Output: ["o","l","l","e","h"]

Example 2:

Input: s = ["H","a","n","n","a","h"]
Output: ["h","a","n","n","a","H"]

Constraints:

• 1 <= s.length <= 105
• s[i] is a printable ascii character.

---

풀이

나의 풀이법

class Solution {
    fun reverseString(s: CharArray) = s.reverse()
}

다른 풀이법

풀이 1

fun reverseString(s: CharArray): Unit {
    var p = 0
    var q = s.size-1
    while (p < q) {
        
        val tempFront = s[p]
        s[p] = s[q]
        s[q] = tempFront
        
        p++
        q--
    }
}

 

풀이 2

 

class Solution {
    fun reverseString(s: CharArray): Unit {
       var j = s.size-1
       for(i in s.indices){
           if(i<j){
           var temp =s[i]
           s[i] = s[j]
           s[j] = temp
           j--
           }else{
               break
           }           
       }
    }
}