feat: Added comment to Stack Implementation for LeetCode Java by Yemi.

lesson_12/structs_java/structs_app/src/main/java/com/codedifferently/lesson12/Lesson12.java

@@ -1,12 +1,15 @@
 package com.codedifferently.lesson12;
 
 public class Lesson12 {
-
-  /**
-   * Provide the solution to LeetCode 3062 here:
-   * https://github.com/yang-su2000/Leetcode-algorithm-practice/tree/master/3062-winner-of-the-linked-list-game
-   */
   public String gameResult(ListNode head) {
-    return null;
+    int result[] = new int[] {0, 0};
+    while (head.next != null) {
+      if (head.val != head.next.val && head.val % 2 == 0) {
+        if (head.val > head.next.val) result[head.val % 2] += 1;
+        else result[head.next.val % 2] += 1;
+      }
+      head = head.next;
+    }
+    return (result[0] == result[1]) ? "Tie" : (result[0] > result[1] ? "Even" : "Odd");
   }
 }

lesson_12/structs_java/structs_app/src/main/java/com/codedifferently/lesson12/Stack.java

@@ -1,6 +1,5 @@
 package com.codedifferently.lesson12;
 
-/** Implement the below Stack by providing code for the class methods. */
 public class Stack {
   private ListNode top;
 
@@ -9,18 +8,30 @@ public Stack() {
   }
 
   public void push(int value) {
-    // Your code here
+    ListNode newNode = new ListNode(value);
+    newNode.next = top;
+    top = newNode;
   }
 
   public int pop() {
-    return 0;
+    int topmostValue = 0;
+    if (isEmpty()) {
+      throw new IllegalStateException("Stack is empty");
+    } else {
+      topmostValue = top.val;
+      top = top.next;
+      return topmostValue;
+    }
   }
 
   public int peek() {
-    return 0;
+    if (isEmpty()) {
+      throw new IllegalStateException("Stack is empty, no value to peek");
+    }
+    return top.val;
   }
 
   public boolean isEmpty() {
-    return true;
+    return top == null;
   }
 }

lesson_12/structs_ts/src/lesson12.ts

@@ -1,11 +1,22 @@
 import { ListNode } from './list_node.js';
 
 export class Lesson12 {
-  /**
-   * Provide the solution to LeetCode 3062 here:
-   * https://github.com/yang-su2000/Leetcode-algorithm-practice/tree/master/3062-winner-of-the-linked-list-game
-   */
   public gameResult(head: ListNode | null): string {
-    return '';
-  }
-}
+    const result: number[] = [0, 0];
+    let current: ListNode | null = head;
+
+    while (current && current.next) {
+        if (current.val !== current.next.val && current.val % 2 === 0) {
+            if (current.val > current.next.val) {
+                result[current.val % 2] += 1;
+            } else {
+                result[current.next.val % 2] += 1;
+            }
+        }
+        current = current.next;
+    }
+    return (result[0] == result[1]) ? 'Tie' : (result[0] > result[1] ? 'Even' : 'Odd');
+ } 
+
+}  
+

lesson_12/structs_ts/src/stack.ts

@@ -8,18 +8,29 @@ export class Stack {
   }
 
   push(value: number): void {
-    throw new Error('Not implemented');
+    const newNode = new ListNode(value);
+    newNode.next = this.top;
+    this.top = newNode;
   }
 
   pop(): number | undefined {
-    throw new Error('Not implemented');
+    let topmostValue = undefined;
+    if (this.isEmpty())
+       throw new Error('No value to pop');
+    else 
+      topmostValue = this.top?.val;  
+      this.top = this.top?.next;
+      return topmostValue
   }
 
   peek(): number | null {
-    throw new Error('Not implemented');
+      if (this.top == undefined) 
+        throw new Error('No value to pop');
+      else
+       return this.top.val;
   }
 
   isEmpty(): boolean {
-    throw new Error('Not implemented');
-  }
+    return (this.top == null);
+  }  
 }