LeetCode 1768. Merge Strings Alternately

Description

https://leetcode.com/problems/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.

Explanation

Similar to merge arrays or linked lists.

Python Solution

class Solution:
    def mergeAlternately(self, word1: str, word2: str) -> str:
        result = ""
        
        i = 0
        j = 0
        
        while i < len(word1) and j < len(word2):        
            if len(result) % 2 == 0:
                result += word1[i]
                i += 1
            else:
                result += word2[j]
                j += 1
        
        while i < len(word1):        
            result += word1[i]
            i += 1

                
        while j < len(word2):
            result += word2[j]
            j += 1
 
        return result
  • Time Complexity: O(N)
  • Space Complexity: O(N)

Leave a Reply

Your email address will not be published.