fork download

copy

from collections import defaultdict
 
def ladderLength(beginWord, endWord, wordList):
 
    if endWord not in wordList or not endWord or not beginWord or not wordList:
        return 0
 
    # Since all words are of same length.
    L = len(beginWord)
 
    # Dictionary to hold combination of words that can be formed,
    # from any given word. By changing one letter at a time.
    all_combo_dict = defaultdict(list)
    for word in wordList:
        for i in range(L):
            # Key is the generic word
            # Value is a list of words which have the same intermediate generic word.
            all_combo_dict[word[:i] + "*" + word[i+1:]].append(word)
 
 
    # Queue for BFS
    queue = collections.deque([(beginWord, 1)])
    # Visited to make sure we don't repeat processing same word.
    visited = {beginWord: True}
    while queue:
        current_word, level = queue.popleft()      
        for i in range(L):
            # Intermediate words for current word
            intermediate_word = current_word[:i] + "*" + current_word[i+1:]
 
            # Next states are all the words which share the same intermediate state.
            for word in all_combo_dict[intermediate_word]:
                # If at any point if we find what we are looking for
                # i.e. the end word - we can return with the answer.
                if word == endWord:
                    return level + 1
                # Otherwise, add it to the BFS Queue. Also mark it visited
                if word not in visited:
                    visited[word] = True
                    queue.append((word, level + 1))
            all_combo_dict[intermediate_word] = []
    return 0
print("pool","cool",["pool","cool"])

prog.cpp:8:7: error: invalid preprocessing directive #Since
     # Since all words are of same length.
       ^~~~~
prog.cpp:11:7: error: invalid preprocessing directive #Dictionary
     # Dictionary to hold combination of words that can be formed,
       ^~~~~~~~~~
prog.cpp:12:7: error: invalid preprocessing directive #from
     # from any given word. By changing one letter at a time.
       ^~~~
prog.cpp:16:15: error: invalid preprocessing directive #Key
             # Key is the generic word
               ^~~
prog.cpp:17:15: error: invalid preprocessing directive #Value
             # Value is a list of words which have the same intermediate generic word.
               ^~~~~
prog.cpp:21:7: error: invalid preprocessing directive #Queue
     # Queue for BFS
       ^~~~~
prog.cpp:23:7: error: invalid preprocessing directive #Visited
     # Visited to make sure we don't repeat processing same word.
       ^~~~~~~
prog.cpp:23:34: warning: missing terminating ' character
     # Visited to make sure we don't repeat processing same word.
                                  ^
prog.cpp:28:15: error: invalid preprocessing directive #Intermediate
             # Intermediate words for current word
               ^~~~~~~~~~~~
prog.cpp:31:15: error: invalid preprocessing directive #Next
             # Next states are all the words which share the same intermediate state.
               ^~~~
prog.cpp:33:19: error: invalid preprocessing directive #If
                 # If at any point if we find what we are looking for
                   ^~
prog.cpp:34:19: error: invalid preprocessing directive #i
                 # i.e. the end word - we can return with the answer.
                   ^
prog.cpp:37:19: error: invalid preprocessing directive #Otherwise
                 # Otherwise, add it to the BFS Queue. Also mark it visited
                   ^~~~~~~~~
prog.cpp:1:1: error: ‘from’ does not name a type
 from collections import defaultdict
 ^~~~
prog.cpp:25:5: error: expected unqualified-id before ‘while’
     while queue:
     ^~~~~

Standard output is empty