Word Ladder ========== **Problem Statement** -------------------- Given a dictionary of words, find the shortest sequence of words such that the first word is the initial word, and the last word is the target word, with each intermediate word differing from its predecessor by exactly one character. **Rules and Constraints** ---------------------- * The dictionary contains a list of words, represented as strings. * Two words are considered distinct if they are not equal and differ by at least one character. * Each word in the final sequence must be present in the dictionary. * The intermediate words in the sequence must satisfy the condition that each word differs from its predecessor by exactly one character. * The length of the input words is guaranteed to be in the range [1, 26]. * The dictionary contains a minimum of 1 word, and a maximum of 10^5 (100,000) words. * The initial word and the target word must be present in the dictionary. * Time complexity: O(n * m^2), where n is the number of words in the dictionary, and m is the maximum length of a word. * Space complexity: O(m), as we need to store the words of the sequence. **Notes** -------- * The problem can be solved using graph traversal algorithms, such as breadth-first search (BFS) or depth-first search (DFS). * The time complexity of the solution can be improved to O(n * m) by using a hash table to store the words that have been visited. ### Example **Input:** {"input_data":[1,2,3]} **Output:** [1,2,3]