[LeetCode][Kotlin] 1768. Merge Strings Alternately

1768. Merge Strings Alternately

You are given two strings word1 and word2. Merge the strings by adding letters in alternating order, starting with word1. If a string is longer than the other, append the additional letters onto the end of the merged string.

 

Return the merged string.

두 개의 문자열 word1과 word2가 주어집니다. word1부터 시작하여 번갈아 가며 문자를 추가하여 문자열을 병합합니다. 문자열이 다른 문자열보다 길면 추가 문자를 병합된 문자열의 끝에 추가합니다. 

병합된 문자열을 반환합니다.

 

Example 1:

Input: word1 = "abc", word2 = "pqr"

Output: "apbqcr"

Explanation: The merged string will be merged as so:

word1:  a   b   c

word2:    p   q   r

merged: a p b q c r

 

Example 2:

Input: word1 = "ab", word2 = "pqrs"

Output: "apbqrs"

Explanation: Notice that as word2 is longer, "rs" is appended to the end.

word1:  a   b 

word2:    p   q   r   s

merged: a p b q   r   s

 

Example 3:

Input: word1 = "abcd", word2 = "pq"

Output: "apbqcd"

Explanation: Notice that as word1 is longer, "cd" is appended to the end.

word1:  a   b   c   d

word2:    p   q 

merged: a p b q c   d

 

Constraints:

• 1 <= word1.length, word2.length <= 100
• word1 and word2 consist of lowercase English letters.

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코드 1

class Solution {
    fun mergeAlternately(word1: String, word2: String): String {
        var answer = ""

        var l1 = 0
        var l2 = 0

        while (l1 < word1.length || l2 < word2.length) {
            if (l1 < word1.length) {
                answer += word1[l1]
            }

            if (l2 < word2.length) {
                answer += word2[l2]
            }

            l1++
            l2++
        }

        return answer
    }
}

 

코드 2

class Solution {
    fun mergeAlternately(word1: String, word2: String): String {
        val res = StringBuilder()

        var i = 0
        var j = 0

        while (i < word1.length && j < word2.length) {
            res.append(word1[i])
            res.append(word2[j])
            i++
            j++
        }

        res.append(word1.drop(i))
        res.append(word2.drop(j))

        return res.toString()
    }
}