Develop

src/app.js

@@ -1,3 +1,45 @@
+/* eslint-disable no-console */
 'use strict';
 
-// Write your code here
+const readline = require('node:readline');
+const { generateRandomNumber } = require('./modules/generateRandomNumber');
+const { checkIsValidUserInput } = require('./modules/checkIsValidUserInput');
+const { getBullsAndCows } = require('./modules/getBullsAndCows');
+
+const rl = readline.createInterface({
+  input: process.stdin,
+  output: process.stdout,
+});
+
+const secretNumber = generateRandomNumber();
+
+function promptUserForGuess() {
+  return new Promise((resolve) => {
+    rl.question('Enter your 4-digit number: ', (userInput) => {
+      resolve(userInput);
+    });
+  });
+}
+
+async function startGame() {
+  try {
+    const userInput = await promptUserForGuess();
+
+    if (checkIsValidUserInput(userInput)) {
+      const result = getBullsAndCows(userInput, secretNumber);
+
+      console.log(result);
+    } else {
+      console.log(
+        // eslint-disable-next-line max-len
+        'Invalid number! Please enter a valid 4-digit number with unique digits.',
+      );
+    }
+  } catch (error) {
+    console.error('An error occurred:', error.message);
+  } finally {
+    rl.close();
+  }
+}
+
+startGame();

src/modules/checkIsValidUserInput.js

@@ -1,17 +1,14 @@
-'use strict';
-
-/**
- * Checks that the user input is valid.
- * Valid user input is a 4-digit number that does not start with 0
- * and does not contain any duplicate digits.
- *
- * @param {string} userInput - The user input
- * @return {boolean} - True if the user input is valid, false otherwise
- */
 function checkIsValidUserInput(userInput) {
-  /* Write your code here */
+  if (
+    userInput.length !== 4 ||
+    userInput[0] === '0' ||
+    !/^\d{4}$/.test(userInput) ||
+    new Set(userInput).size !== 4
+  ) {
+    return false;
+  }
+
+  return true;
 }
 
-module.exports = {
-  checkIsValidUserInput,
-};
+module.exports = { checkIsValidUserInput };

src/modules/generateRandomNumber.js

@@ -1,15 +1,13 @@
-'use strict';
-
-/**
- * Generate a random 4-digit number that does not start with 0
- * and does not contain any duplicate digits.
- *
- * @return {number} A random 4-digit number
- */
+/* eslint-disable no-console */
+/* eslint-disable padding-line-between-statements */
 function generateRandomNumber() {
-  /* Write your code here */
+  let randomNumber;
+
+  do {
+    randomNumber = Math.floor(Math.random() * 9000) + 1000;
+  } while (new Set(randomNumber.toString()).size !== 4);
+
+  return randomNumber;
 }
 
-module.exports = {
-  generateRandomNumber,
-};
+module.exports = { generateRandomNumber };

src/modules/getBullsAndCows.js

@@ -1,21 +1,28 @@
-'use strict';
+function getBullsAndCows(userInput, targetNumber) {
+  const userInputStr = userInput.toString();
+  const targetNumberStr = targetNumber.toString();
+  const result = { bulls: 0, cows: 0 };
+  const targetNumberDigits = Array.from(targetNumberStr);
 
-/**
- * Calculate the number of bulls and cows for a given user input.
- * Bulls are digits that are in the correct position.
- * Cows are digits that are in the wrong position.
- * Assume that the user input and the number to guess
- * are always 4-digit numbers.
- *
- * @param {number} userInput - The user input
- * @param {number} numberToGuess - The number to guess
- * @return {object} An object containing the number of bulls and cows.
- * Example: { bulls: 1, cows: 2 }
- */
-function getBullsAndCows(userInput, numberToGuess) {
-  /* Write your code here */
+  for (let i = 0; i < targetNumberStr.length; i++) {
+    if (userInputStr[i] === targetNumberStr[i]) {
+      result.bulls += 1;
+      targetNumberDigits[i] = null;
+    }
+  }
+
+  for (let i = 0; i < targetNumberStr.length; i++) {
+    if (userInputStr[i] !== targetNumberStr[i]) {
+      const indexInGuess = targetNumberDigits.indexOf(userInputStr[i]);
+
+      if (indexInGuess !== -1) {
+        result.cows += 1;
+        targetNumberDigits[indexInGuess] = null;
+      }
+    }
+  }
+
+  return result;
 }
 
-module.exports = {
-  getBullsAndCows,
-};
+module.exports = { getBullsAndCows };