gistfile1.txt

from collections import deque
import string

def string_transformation(words, start, stop):
    """
    Args:
     words(list_str)
     start(str)
     stop(str)
    Returns:
     list_str
    """
    # create set for dict
    word_dict = set(words)
    #create queue, visited, distance
    q = deque()
    q.append((list(start)))
    
    n = 26
    visited = set()
    parent = {} # map of map to trace the path
    res = []
    while q:
        curr_word = q.popleft()
        curr_word_str = "".join(curr_word)

        for i in range(len(start)):
            old_char = curr_word[i]
            word_str = ''.join(curr_word)
            
            if word_str == stop:
                res = []
                while(word_str in parent):
                    word_str = parent[word_str]
                    res.append(word_str)
                return res  
            for ch in list(string.ascii_lowercase):
                curr_word[i]=ch 
                word_str = ''.join(curr_word)
                if word_str not in visited or word_str == stop:
                    if word_str in word_dict or word_str == stop :
                        visited.add(word_str)
                        parent[word_str] = curr_word_str
                        q.append(list(curr_word.copy()))
                        res.append(str(word_str))
                curr_word[i] = old_char
    '''
    #change the first char
    put a to z in its place and if in dictionary, then
    increment distance for that r and col
    #
    '''
    
    return ["-1"]