Longest Palindrome by Concatenating Two Letter Words - Solution & Explanation

The first approach involves counting occurrences of each word and its reverse. If a word appears with its reverse, they can be directly paired to contribute to the palindrome length. Symmetrical words like 'gg' can be used optimally to form palindromes, with one potentially serving as a center if their count is odd.

The C solution uses a manual structure to count word occurrences and then utilizes sorting and dual iterations to pair words and compute maximum palindrome length. Reversals are computed for each word, ensuring that all possible pairs contribute optimally to the palindrome length.

This approach involves creating a hash map to quickly check for the existence of a word's reverse in the input, allowing us to efficiently pair words or use symmetric words optimally. We calculate pairs and handle middle contributions by taking account of unsused symmetric words.

This C solution employs a two-dimensional array approach (map) to store the frequency of character pairs. It counts how many of each type of word pair exist and checks for their reversal, adding contributions to the length based on pair formation. It separately checks for symmetrical pairs to add potential middle characters.