Add Stack.

src/data-structures/queue/Queue.js

@@ -10,19 +10,19 @@ export default class Queue {
   }
 
   peek() {
-    if (!this.linkedList.tail) {
+    if (!this.linkedList.head) {
       return null;
     }
 
-    return this.linkedList.tail.value;
+    return this.linkedList.head.value;
   }
 
-  add(value) {
+  enqueue(value) {
     this.linkedList.append({ value });
   }
 
-  remove() {
-    const removedTail = this.linkedList.deleteTail();
-    return removedTail ? removedTail.value : null;
+  dequeue() {
+    const removedHead = this.linkedList.deleteHead();
+    return removedHead ? removedHead.value : null;
   }
 }

src/data-structures/queue/README.md

@@ -1,8 +1,2 @@
 # Queue
 
-|Operation                  |Complexity         |
-|---------------------------|-------------------|
-|Find                       |O()               |
-|Insert/delete at beginning |O()               |
-|Insert/delete in middle    |O() |
-|Insert/delete at end       |O() |

src/data-structures/queue/__test__/Queue.test.js

@@ -7,11 +7,11 @@ describe('Queue', () => {
     expect(queue.linkedList).not.toBeNull();
   });
 
-  it('should add data to queue', () => {
+  it('should enqueue data to queue', () => {
     const queue = new Queue();
 
-    queue.add(1);
-    queue.add(2);
+    queue.enqueue(1);
+    queue.enqueue(2);
 
     expect(queue.linkedList.toString()).toBe('1,2');
   });
@@ -21,11 +21,11 @@ describe('Queue', () => {
 
     expect(queue.peek()).toBeNull();
 
-    queue.add(1);
-    queue.add(2);
+    queue.enqueue(1);
+    queue.enqueue(2);
 
-    expect(queue.peek()).toBe(2);
-    expect(queue.peek()).toBe(2);
+    expect(queue.peek()).toBe(1);
+    expect(queue.peek()).toBe(1);
   });
 
   it('should check if queue is empty', () => {
@@ -33,19 +33,19 @@ describe('Queue', () => {
 
     expect(queue.isEmpty()).toBeTruthy();
 
-    queue.add(1);
+    queue.enqueue(1);
 
     expect(queue.isEmpty()).toBeFalsy();
   });
 
-  it('should remove from empty', () => {
+  it('should dequeue from queue in FIFO order', () => {
     const queue = new Queue();
 
-    queue.add(1);
-    queue.add(2);
+    queue.enqueue(1);
+    queue.enqueue(2);
 
-    expect(queue.remove()).toBe(2);
-    expect(queue.remove()).toBe(1);
+    expect(queue.dequeue()).toBe(1);
+    expect(queue.dequeue()).toBe(2);
     expect(queue.isEmpty()).toBeTruthy();
   });
 });