Create 299-bulls-and-cows.js

Author: everthis

299-bulls-and-cows.js

@@ -0,0 +1,29 @@
+/**
+ * @param {string} secret
+ * @param {string} guess
+ * @return {string}
+ */
+const getHint = function(secret, guess) {
+  let bulls = 0
+  let cows = 0
+  const h = {}
+  for(let i = 0, len = secret.length; i < len; i++) {
+    if(secret[i] === guess[i]) {
+      bulls++
+    } else {
+      if(!h.hasOwnProperty(secret[i])) h[secret[i]] = 0
+      h[secret[i]]++
+    }
+  }
+  
+  for(let i = 0, len = secret.length; i < len; i++) {
+    if(secret[i] !== guess[i]) {
+      if(h.hasOwnProperty(guess[i]) && h[guess[i]] > 0) {
+        cows++
+        h[guess[i]]--
+      }
+    }
+  }
+
+  return `${bulls}A${cows}B`
+};