diff --git a/04week/mastermind.js b/04week/mastermind.js
index 60e5cfa18..4fc2745f8 100644
--- a/04week/mastermind.js
+++ b/04week/mastermind.js
@@ -11,6 +11,8 @@ let board = [];
 let solution = '';
 let letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
 
+ 
+
 function printBoard() {
   for (let i = 0; i < board.length; i++) {
     console.log(board[i]);
@@ -28,16 +30,45 @@ function getRandomInt(min, max) {
   return Math.floor(Math.random() * (max - min)) + min;
 }
 
-function generateHint() {
-  // your code here
+function generateHint(solution, guess) {
+  let solutionArray = solution.split('');
+  let guessArray = guess.split('');
+  let correctLetterLocations = 0;
+  for (let i=0; i<solutionArray.length; i++) {
+    if (solutionArray[i] == guessArray[i]){
+    correctLetterLocations = correctLetterLocations + 1;
+    solutionArray[i] = null;
+   }
+  }
+  let correctLetters = 0;
+  for (let j=0; j<solutionArray.length; j++){
+   let targetIndex = guessArray.indexOf(solutionArray[j]);
+    if (targetIndex > -1) {
+        correctLetters = correctLetters + 1;
+        solutionArray[j] = null;
+        }
+    }
+    return correctLetterLocations+"-" + correctLetters;
+    //fancier hint generator that the NPM tests won't like:
+    // return correctLetterLocations+" correct and " + correctLetters + " in the wrong place";
 }
+ 
 
 function mastermind(guess) {
-  solution = 'abcd'; // Comment this out to generate a random solution
-  // your code here
+  solution = 'abcd';
+  if (board.length >= 10){
+    console.log('You ran out of guesses!')
+  } else {
+    if (guess != solution) {
+      let hints = generateHint(solution, guess);
+      board.push(hints)
+    } else {
+      console.log('You guessed it!');
+      return 'You guessed it!';
+    }
+  }
 }
 
-
 function getPrompt() {
   rl.question('guess: ', (guess) => {
     mastermind(guess);
@@ -59,19 +90,15 @@ if (typeof describe === 'function') {
       assert.equal(mastermind(solution), 'You guessed it!');
     });
   });
-
   describe('#generateHint()', () => {
     it('should generate hints', () => {
-      assert.equal(generateHint('abdc'), '2-2');
+      assert.equal(generateHint(solution, 'abdc'), '2-2');
     });
     it('should generate hints if solution has duplicates', () => {
-      assert.equal(generateHint('aabb'), '1-1');
+      assert.equal(generateHint(solution, 'aabb'), '1-1');
     });
-
   });
-
 } else {
-
   generateSolution();
   getPrompt();
-}
+}
\ No newline at end of file