# 1768. Merge Strings Alternately - LeetCode Python/Java/C++/JS/C#/Go/Ruby Solutions Visit original link: [1768. Merge Strings Alternately - LeetCode Python/Java/C++/JS/C#/Go/Ruby Solutions](https://leetcode.to/en/leetcode/1768-merge-strings-alternately) for a better experience! LeetCode link: [1768. Merge Strings Alternately](https://leetcode.com/problems/merge-strings-alternately), difficulty: **Easy**. ## LeetCode description of "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. ### [Hints]
Hint 1 Use two pointers, one pointer for each string. Alternately choose the character from each pointer, and move the pointer upwards.
## Intuition The problem asks us to merge two strings, `word1` and `word2`, by taking characters alternately, starting with `word1`. If one string is longer than the other, the remaining characters of the longer string should be appended to the end of the merged result. The core idea is to iterate through both strings simultaneously, picking one character from `word1` and then one from `word2`, and adding them to our result. This process continues as long as we have characters available in *both* strings. Once we run out of characters in the shorter string, we simply take all the remaining characters from the longer string and append them to our result. ## Step-by-Step Solution 1. Initialize an empty string (or a list of characters, or a string builder) to store the merged result. 2. Determine the lengths of `word1` and `word2`. Let these be `n1` and `n2`. 3. Find the minimum of these two lengths, say `min_len = min(n1, n2)`. This `min_len` is the number of characters we can pick alternately from both strings. 4. Iterate from `i = 0` up to `min_len - 1`: - Append the `i`-th character of `word1` to the result. - Append the `i`-th character of `word2` to the result. 5. After the loop, we have processed `min_len` characters from both strings. 6. Determine which string potentially has leftover characters. Let this be `longer_word`. - If the length of `word1` (`n1`) is greater than `min_len`, then `longer_word` is `word1`. - Otherwise `longer_word` is `word2`. 7. Append the remaining part of `longer_word` (i.e., `longer_word` from index `min_len` onwards) to the `result`. 8. Return the final merged string. ## Complexity - Time complexity: `O(N)`. - Space complexity: `O(N)`. ## Python ```python class Solution: def mergeAlternately(self, word1: str, word2: str) -> str: min_size = min(len(word1), len(word2)) result = "" for i in range(min_size): result += f'{word1[i]}{word2[i]}' longer_word = word1 if len(word1) > min_size else word2 return result + longer_word[min_size:] ``` ## Java ```java class Solution { public String mergeAlternately(String word1, String word2) { int minSize = Math.min(word1.length(), word2.length()); StringBuilder result = new StringBuilder(); for (int i = 0; i < minSize; i++) { result.append(word1.charAt(i)).append(word2.charAt(i)); } String longerWord = (word1.length() > word2.length()) ? word1 : word2; result.append(longerWord.substring(minSize)); return result.toString(); } } ``` ## C++ ```cpp class Solution { public: string mergeAlternately(string word1, string word2) { int min_size = min(word1.length(), word2.length()); string result; for (int i = 0; i < min_size; ++i) { result += word1[i]; result += word2[i]; } auto& longer_word = (word1.length() > min_size) ? word1 : word2; result += longer_word.substr(min_size); return result; } }; ``` ## JavaScript ```javascript var mergeAlternately = function(word1, word2) { const minSize = Math.min(word1.length, word2.length); let result = ""; for (let i = 0; i < minSize; i++) { result += word1[i] + word2[i]; } const longerWord = word1.length > word2.length ? word1 : word2; result += longerWord.slice(minSize); return result; }; ``` ## Go ```go func mergeAlternately(word1, word2 string) string { minSize := int(math.Min(float64(len(word1)), float64(len(word2)))) var result strings.Builder for i := 0; i < minSize; i++ { result.WriteByte(word1[i]) result.WriteByte(word2[i]) } longerWord := word1 if len(word2) > len(word1) { longerWord = word2 } result.WriteString(longerWord[minSize:]) return result.String() } ``` ## C# ```csharp public class Solution { public string MergeAlternately(string word1, string word2) { int minSize = Math.Min(word1.Length, word2.Length); var result = new StringBuilder(); for (int i = 0; i < minSize; i++) result.Append(word1[i]).Append(word2[i]); string longerWord = word1.Length > word2.Length ? word1 : word2; result.Append(longerWord.Substring(minSize)); return result.ToString(); } } ``` ## Ruby ```ruby def merge_alternately(word1, word2) min_size = [ word1.size, word2.size ].min result = "" min_size.times { |i| result << word1[i] << word2[i] } longer_word = word1.size > word2.size ? word1 : word2 result << longer_word[min_size..] result end ``` ## Other languages ```java // Welcome to create a PR to complete the code of this language, thanks! ``` Dear LeetCoders! For a better LeetCode problem-solving experience, please visit website [LeetCode.to](https://leetcode.to): Dare to claim the best practices of LeetCode solutions! Will save you a lot of time! Original link: [1768. Merge Strings Alternately - LeetCode Python/Java/C++/JS/C#/Go/Ruby Solutions](https://leetcode.to/en/leetcode/1768-merge-strings-alternately). GitHub repository: [leetcode-python-java](https://github.com/leetcode-python-java/leetcode-python-java).