organize LL methods

201flaviosilva · May 22, 2023 · fe1a0a4 · fe1a0a4
1 parent f735de7
commit fe1a0a4
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Showing 2 changed files with 67 additions and 52 deletions.
diff --git a/src/DataStructures/LinkedList.js b/src/DataStructures/LinkedList.js
@@ -37,7 +37,7 @@ export class LinkedList {
 		return this;
 	}
 
-	// Add a new value to the END of the list
+	// ADD a new value to the END of the list
 	push(value) {
 		const newNode = new Node(value);
 		if (!this.head) {
@@ -52,7 +52,26 @@ export class LinkedList {
 		return this;
 	}
 
-	// Remove a value from the END of the list
+	// ADD a new value to the START of the list
+	unshift(value) {
+		const newNode = new Node(value);
+		newNode.next = this.head;
+		this.head = newNode;
+
+		if (!this.tail) this.tail = newNode;
+
+		this.size++;
+
+		return this;
+	}
+
+
+	// ADD a new value to the given index of the list
+	insert(value, index) {
+		return this;
+	}
+
+	// REMOVE a value from the END of the list
 	pop() {
 		if (!this.size) return undefined;
 
@@ -72,21 +91,17 @@ export class LinkedList {
 		return temp.value;
 	}
 
-	// Add a new value to the BEGINNING of the list
-	unshift(value) {
-		const newNode = new Node(value);
-		newNode.next = this.head;
-		this.head = newNode;
-
-		if (!this.tail) this.tail = newNode;
-
-		this.size++;
+	// REMOVE a value to the START of the list
+	shift() {
+		return this;
+	}
 
+	// REMOVE a value in the given index of the list
+	remove(value, index) {
 		return this;
 	}
 
-	// Add a new value to the given index of the list
-	insert(value, index) {
+	reverse() {
 		return this;
 	}
 

diff --git a/tests/DataStructures/LinkedList.test.js b/tests/DataStructures/LinkedList.test.js
@@ -60,6 +60,45 @@ describe("LinkedList.js", () => {
 			});
 		});
 
+		describe("unshift()", () => {
+			it("should add a new element at the start", () => {
+				const ll = new LinkedList(0);
+
+				ll.unshift(10);
+				expect(ll.size).toBe(2);
+				expect(ll.head.value).toBe(10);
+				expect(ll.tail.value).toBe(0);
+				expect(ll.tail.next).toBe(null);
+				expect(ll.toArray()).toEqual([10, 0]);
+
+				ll.unshift(20);
+				expect(ll.size).toBe(3);
+				expect(ll.head.value).toBe(20);
+				expect(ll.tail.value).toBe(0);
+				expect(ll.tail.next).toBe(null);
+				expect(ll.toArray()).toEqual([20, 10, 0]);
+			});
+
+			it("should add a new element if the list is empty", () => {
+				const ll = new LinkedList();
+				expect(ll.size).toBe(0);
+
+				ll.unshift(1);
+				expect(ll.size).toBe(1);
+				expect(ll.head.value).toBe(1);
+				expect(ll.tail.value).toBe(1);
+				expect(ll.tail.next).toBe(null);
+				expect(ll.toArray()).toEqual([1]);
+
+				ll.unshift(10);
+				expect(ll.size).toBe(2);
+				expect(ll.head.value).toBe(10);
+				expect(ll.tail.value).toBe(1);
+				expect(ll.tail.next).toBe(null);
+				expect(ll.toArray()).toEqual([10, 1]);
+			});
+		});
+
 		describe("pop()", () => {
 			it("remove the last element from the linked list", () => {
 				const ll = new LinkedList(100);
@@ -102,45 +141,6 @@ describe("LinkedList.js", () => {
 			});
 		});
 
-		describe("unshift()", () => {
-			it("should add a new element at the start", () => {
-				const ll = new LinkedList(0);
-
-				ll.unshift(10);
-				expect(ll.size).toBe(2);
-				expect(ll.head.value).toBe(10);
-				expect(ll.tail.value).toBe(0);
-				expect(ll.tail.next).toBe(null);
-				expect(ll.toArray()).toEqual([10, 0]);
-
-				ll.unshift(20);
-				expect(ll.size).toBe(3);
-				expect(ll.head.value).toBe(20);
-				expect(ll.tail.value).toBe(0);
-				expect(ll.tail.next).toBe(null);
-				expect(ll.toArray()).toEqual([20, 10, 0]);
-			});
-
-			it("should add a new element if the list is empty", () => {
-				const ll = new LinkedList();
-				expect(ll.size).toBe(0);
-
-				ll.unshift(1);
-				expect(ll.size).toBe(1);
-				expect(ll.head.value).toBe(1);
-				expect(ll.tail.value).toBe(1);
-				expect(ll.tail.next).toBe(null);
-				expect(ll.toArray()).toEqual([1]);
-
-				ll.unshift(10);
-				expect(ll.size).toBe(2);
-				expect(ll.head.value).toBe(10);
-				expect(ll.tail.value).toBe(1);
-				expect(ll.tail.next).toBe(null);
-				expect(ll.toArray()).toEqual([10, 1]);
-			});
-		});
-
 		describe("toArray()", () => {
 			it("should return an array with the values of the linked list", () => {
 				const ll = new LinkedList(0);