Skip to content

Latest commit

 

History

History
42 lines (32 loc) · 2.48 KB

1768-Merge-Strings-Alternately.md

File metadata and controls

42 lines (32 loc) · 2.48 KB

Merge Strings Alternately

Intuition

The problem requires merging two strings, word1 and word2, by alternating their characters, starting with word1. If one string is longer than the other, the remaining characters from the longer string should be appended to the end of the merged result. The goal is to create a merged string that reflects this alternating pattern while efficiently handling the possibility of differing string lengths.

Approach

  1. Initialization: Start by creating a StringBuilder to hold the merged result, initialized with a capacity equal to the combined length of word1 and word2. This optimizes memory usage and avoids repeated resizing during the appending process.
  2. Two-Pointer Technique: Utilize two pointers, i and j, initialized at the start of word1 and word2, respectively. Use a while loop to iterate through both strings as long as there are characters available in both strings:
    • Append the character from word1 at position i and then increment i.
    • Append the character from word2 at position j and then increment j.
  3. Appending Remaining Characters: After exiting the loop (when either string is exhausted), use the substring method to append any remaining characters from word1 or word2 to the result. This step handles cases where one string is longer than the other.
  4. Return the Result: Convert the StringBuilder to a string and return it as the final merged result.

Complexity

  • Time Complexity: O(m+n), where n is the length of word1 and m is the length of word2. This is because each character from both strings is processed exactly once.
  • Space Complexity: O(m+n), mainly due to the space used by the StringBuilder, which stores the merged string of length equal to the sum of word1 and word2.

Code

Summary

The solution effectively merges two strings by alternating their characters using a two-pointer technique. By leveraging a StringBuilder, the approach ensures efficient string manipulation and minimizes unnecessary memory usage. This method handles differing string lengths gracefully by appending any remaining characters once one string is exhausted, making the solution both time and space efficient. The overall design is straightforward, making the code easy to read and maintain.