Update 02_recursive_binary_search.js (egonSchiele#125)

hero1292 · egonSchiele · commit ee7dcd3b3d02 · 2019-10-30T16:31:50.000-05:00
diff --git a/01_introduction_to_algorithms/ES6/02_recursive_binary_search.js b/01_introduction_to_algorithms/ES6/02_recursive_binary_search.js
@@ -7,25 +7,20 @@
  * @return {(number | null)} Number if the value is found or NULL otherwise
  */
 const binarySearch = ( list, item, low = 0, high = list.length - 1 ) => {
-    let arrLength = list.length;
-    while ( low <= high ) {
-        let mid = Math.floor((low + high) / 2);
-        let guess = list[mid];
+    let mid = Math.floor((low + high) / 2);
+    let guess = list[mid];
 
-        if ( guess === item ) {
-            return mid;
-        } else if ( guess > item ) {
-            high = mid - 1;
-            list = list.slice( 0, mid );
-            return binarySearch( list, item, low, high );
-        } else {
-            low = mid + 1;
-            list = list.slice( low, arrLength );
-            return binarySearch( list, item, low, high );
-        }
-    }
+    if ( low > high ) return null;
 
-    return null;
+    if ( guess === item ) {
+        return mid;
+    } else if ( guess > item ) {
+        high = mid - 1;
+        return binarySearch( list, item, low, high );
+    } else {
+        low = mid + 1;
+        return binarySearch( list, item, low, high );
+    }
 };
 
 /**
