[LeetCode]#1768. Merge Strings Alternately

Environment: Python 3.8

Key technique: itertools.zip_longest

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

Analysis:

1. Use itertool.zip_longest for word1 and word2.
2. Use loop to add each tuple in list

Solution:

import itertools
class Solution:
    def mergeAlternately(self, word1, word2):
        ans=""
        for i, j in itertools.zip_longest(word1, word2, fillvalue=""):
          ans=ans+i+j
        return ans

Submissions:

Reference:

https://leetcode.com/problems/merge-strings-alternately/discuss/1078557/My-Python-Solution

https://medium.com/@ot32em/python-%E7%9C%8B%E5%88%B0%E4%B8%80%E5%80%8B-grouper-%E7%9A%84%E5%AF%AB%E6%B3%95-bf868255c9ff