I always talk about how programming languages are just tools we use to communicate with computers. To clarify this, let me give you the following example: You are fluent in English and want to express your sadness by saying, "I am sad." You could also say, "I'm feeling down" or "I'm heartbroken." We agreed that you are sad, but the beautiful girl you are trying to impress with your imaginary sadness does not speak English. She is from China, and unfortunately, you do not know Chinese. Let me ask you this: Is your desire to woo this girl gone just because you can't speak her language? Is the approach your mind created to impress and seduce this girl inappropriate just because you can't speak her language? The answer to both questions is no. By projecting this onto programming, we can say that your ability to write in a specific programming language does not necessarily mean you can solve programming problems, even if you master the language 100 percent. The evidence for this is that even if you could speak Chinese in the previous example, the way to seduce a girl by making her feel sad is vulgar and ridiculous. In this post, I will solve a problem presented by Google and explain the solution in detail. However, I want to draw your attention to the importance of learning algorithms and data structures. ** Guess the Word ** Given an array of unique six-letter strings words, where each string in words[i] is guaranteed to be six letters long, one string has been selected as a secret word. You are also provided with a helper object called Master. You can use Master.guess(word), where word is a six-letter string from words. The method Master.guess(word) will return: -1 if the word is not present in words. An integer representing the number of exact matches (both value and position) between your guess and the secret word. Each test case comes with a parameter allowedGuesses, indicating the maximum number of times you can call Master.guess(word). For each test case, your goal is to identify the secret word by calling Master.guess without exceeding the number of allowed guesses. You will get: "Either you took too many guesses, or you did not find the secret word." if you either exceed the allowed number of guesses or fail to guess the secret word. "You guessed the secret word correctly." if you guess the secret word within the allowed number of guesses. The test cases are designed to ensure that it is possible to guess the secret word using a reasonable strategy, excluding brute force methods. Example: 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. ** Let's Simplify it: ** You have a list of unique six-letter words and need to find a secret word among them. To do this, you can make guesses, each time receiving feedback on how many letters in your guess match exactly with the secret word. Your task is to guess the secret word correctly within a given number of attempts. The challenge is to use each guess effectively to narrow down the list of possible words based on the feedback you get, so you can identify the secret word efficiently without exceeding the allowed number of guesses. The feedback you receive tells you how many letters in your guess are in the correct position, which helps you filter out words that don't match. ** How To Solve it: ** To solve the problem, I'll start by using a simple strategy to guess the secret word. First, I'll make a guess from the list of possible words. Based on the feedback from this guess, which tells me how many letters match exactly in the correct positions, I'll filter out the words that don't match this feedback. I'll continue making guesses and updating the list of possible words based on the feedback after each guess. To do this, I'll use a list to keep track of all possible words and a simple function to count how many letters match between any two words. This approach uses basic algorithms for filtering and updating the list and ensures I make efficient guesses within the allowed number of attempts. ** The Algorithm: ** **Step 1:** Initialize the maximum number of allowed guesses and the list of possible words. **Step 2:** Define a helper function getMatchCount that counts how many characters match exactly between two given words. **Step 3:** Define a helper function guessAndFilter: - Make a guess using the Master API to get feedback on the number of exact matches. - If the feedback indicates all positions match (i.e., 6), return true to indicate the guess is correct. - Otherwise, filter the list of possible words to keep only those that match the exact number of positions as the guess. ** Step 4:** Start the guessing process: -Initialize an attempt counter. - While the number of attempts is less than the allowed guesses and the list of possible words is not empty: a- Increment the attempt counter. b- Choose a word from the list as the guess. c- Use guessAndFilter to get feedback and update the list of possible words. d- If the guess is correct, print a success message and exit. ** The Code: ** Personally, I can write the solution using PHP, Python, or Java, but regardless of the language I use, I have already solved the problem. ```php class Solution { /** * @param String[] $words * @param Master $master * @return void */ function findSecretWord($words, $master) { $allowedGuesses = 10; $this->attemptGuess($words, $master, $allowedGuesses); } private function getMatchCount($word1, $word2) { $count = 0; for ($i = 0; $i < 6; $i++) { if ($word1[$i] === $word2[$i]) { $count++; } } return $count; } private function guessAndFilter($guess, $words, $master) { $matches = $master->guess($guess); if ($matches == 6) { return true; } $newWords = []; foreach ($words as $word) { if ($this->getMatchCount($word, $guess) === $matches) { $newWords[] = $word; } } return $newWords; } private function attemptGuess($words, $master, $allowedGuesses) { $attempts = 0; while ($attempts < $allowedGuesses && !empty($words)) { $attempts++; $guess = $words[0]; $result = $this->guessAndFilter($guess, $words, $master); if ($result === true) { echo "You guessed the secret word correctly."; return; } $words = $result; } echo "Either you took too many guesses, or you did not find the secret word."; } } ``` Good Luck,