Guess The Word

Problem Statement

You are given an array of unique strings words where words[i] is six letters long. One word of words was chosen as a secret word.

You are also given the helper object Master. You may call Master.guess(word) where word is a six-letter-long string, and it must be from words. Master.guess(word) returns:

• -1 if word is not from words, or
• an integer representing the number of exact matches (value and position) of your guess to the secret word.

There is a parameter allowedGuesses for each test case where allowedGuesses is the maximum number of times you can call Master.guess(word).

For each test case, you should call Master.guess with the secret word without exceeding the maximum number of allowed guesses. You will get:

• "Either you took too many guesses, or you did not find the secret word." if you called Master.guess more than allowedGuesses times or if you did not call Master.guess with the secret word, or
• "You guessed the secret word correctly." if you called Master.guess with the secret word with the number of calls to Master.guess less than or equal to allowedGuesses.

The test cases are generated such that you can guess the secret word with a reasonable strategy (other than using the bruteforce method).

LeetCode Link

Example 1:

Input: secret = "acckzz", words = ["acckzz","ccbazz","eiowzz","abcczz"], allowedGuesses = 10
Output: You guessed the secret word correctly.
Explanation:
master.guess("aaaaaa") returns -1, because "aaaaaa" is not in wordlist.
master.guess("acckzz") returns 6, because "acckzz" is secret and has all 6 matches.
master.guess("ccbazz") returns 3, because "ccbazz" has 3 matches.
master.guess("eiowzz") returns 2, because "eiowzz" has 2 matches.
master.guess("abcczz") returns 4, because "abcczz" has 4 matches.
We made 5 calls to master.guess, and one of them was the secret, so we pass the test case.

Example 2:

Input: secret = "hamada", words = ["hamada","khaled"], allowedGuesses = 10
Output: You guessed the secret word correctly.
Explanation: Since there are two words, you can guess both.

Constraints:

• 1 <= words.length <= 100
• words[i].length == 6
• words[i] consist of lowercase English letters.
• All the strings of wordlist are unique.
• secret exists in words.
• 10 <= allowedGuesses <= 30

Code

Python

class Solution(object):
    def findSecretWord(self, wordlist, master):

        def pair_matches(a, b):         # count the number of matching characters
            return sum(c1 == c2 for c1, c2 in zip(a, b))

        def most_overlap_word():
            counts = [[0 for _ in range(26)] for _ in range(6)]     # counts[i][j] is nb of words with char j at index i
            for word in candidates:
                for i, c in enumerate(word):
                    counts[i][ord(c) - ord("a")] += 1

            best_score = 0
            for word in candidates:
                score = 0
                for i, c in enumerate(word):
                    score += counts[i][ord(c) - ord("a")]           # all words with same chars in same positions
                if score > best_score:
                    best_score = score
                    best_word = word

            return best_word

        candidates = wordlist[:]        # all remaining candidates, initially all words
        while candidates:

            s = most_overlap_word()     # guess the word that overlaps with most others
            matches = master.guess(s)

            if matches == 6:
                return

            candidates = [w for w in candidates if pair_matches(s, w) == matches]