Largest merge of two strings

We will iterate through the two strings and compare the current character of each string. If the current character of word1 is greater than the current character of word2, we will add the current character of word1 to the result and increment the index of word1. Otherwise, we will add the current character of word2 to the result and increment the index of word2. We will return the result.

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

Time complexity: O(n+m)
Space complexity: O(n+m)