node_bulls-and-cows

src/app.js

@@ -1,3 +1,12 @@
 'use strict';
 
-// Write your code here
+const { checkIsValidUserInput } = require('./modules/checkIsValidUserInput');
+const { generateRandomNumber } = require('./modules/generateRandomNumber');
+const { getBullsAndCows } = require('./modules/getBullsAndCows');
+
+const numberToGuess = generateRandomNumber();
+const userInput = +process.argv.slice(2)[0];
+
+if (checkIsValidUserInput(userInput)) {
+  getBullsAndCows(userInput, numberToGuess);
+}

src/modules/checkIsValidUserInput.js

@@ -9,7 +9,23 @@
  * @return {boolean} - True if the user input is valid, false otherwise
  */
 function checkIsValidUserInput(userInput) {
-  /* Write your code here */
+  const notNumber = isNaN(+userInput);
+
+  if (notNumber) {
+    return false;
+  }
+
+  if (userInput[0] === '0' || userInput.length !== 4) {
+    return false;
+  }
+
+  for (let i = 0; i < userInput.length; i++) {
+    if (userInput.slice(0, i).includes(userInput[i])) {
+      return false;
+    }
+  }
+
+  return true;
 }
 
 module.exports = {

src/modules/generateRandomNumber.js

@@ -7,7 +7,23 @@
  * @return {number} A random 4-digit number
  */
 function generateRandomNumber() {
-  /* Write your code here */
+  const numbers = [];
+  const [start, end] = [1, 9];
+
+  for (let i = start; i <= end; i++) {
+    numbers.push(i);
+  }
+
+  let result = '';
+
+  for (let i = 0; i < 4; i++) {
+    const roundIndex = Math.floor(Math.random() * numbers.length);
+
+    result += numbers[roundIndex];
+    numbers.splice(roundIndex, 1);
+  }
+
+  return +result;
 }
 
 module.exports = {

src/modules/getBullsAndCows.js

@@ -13,7 +13,23 @@
  * Example: { bulls: 1, cows: 2 }
  */
 function getBullsAndCows(userInput, numberToGuess) {
-  /* Write your code here */
+  const result = {
+    bulls: 0,
+    cows: 0,
+  };
+
+  const userNumber = userInput.toString();
+  const guessNumber = numberToGuess.toString();
+
+  for (let i = 0; i < userNumber.length; i++) {
+    if (userNumber[i] === guessNumber[i]) {
+      result.bulls++;
+    } else if (guessNumber.includes(userNumber[i])) {
+      result.cows++;
+    }
+  }
+
+  return result;
 }
 
 module.exports = {