[LeetCode 75] Easy - 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.

 

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.

https://youtu.be/LECWOvTo-Sc?si=3GxC3IS6WPGVq43t

 

class Solution:
    def mergeAlternately(self, word1: str, word2: str) -> str:
        idx1, idx2 = 0, 0
        
        res = []
        while idx1 < len(word1) and idx2 < len(word2):
            res.append(word1[idx1])
            res.append(word2[idx2])
            idx1 +=1
            idx2 +=1
        
        res.append(word1[idx1:])
        res.append(word2[idx2:])

        return ''.join(res)