Implemented the gameResult and stack methods

Author: RMillerCohort251

lesson_12/structs_ts/src/lesson12.ts

@@ -1,11 +1,29 @@
 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 '';
-  }
+     if (!head) return 'Tie';
+    
+    const ls = [0, 0];
+    
+    while (head.next) {
+        if (head.val !== head.next.val && head.val % 2 === 0) {
+            if (head.val > head.next.val) {
+                ls[head.val % 2] += 1;
+            } else {
+                ls[head.next.val % 2] += 1;
+            }
+        }
+        head = head.next;
+    }
+    
+    if (ls[0] === ls[1]) {
+        return 'Tie';
+    } else if (ls[0] > ls[1]) {
+        return 'Even';
+    } else {
+        return 'Odd';
+    }
+}
 }

lesson_12/structs_ts/src/stack.ts

@@ -1,25 +1,36 @@
 import { ListNode } from './list_node.js';
 
 export class Stack {
-  private top: ListNode | undefined;
+  private top: ListNode | null;
 
   constructor() {
-    this.top = undefined;
+    this.top = null;
   }
 
   push(value: number): void {
-    throw new Error('Not implemented');
+    const newNode = new ListNode(value, this.top ?? undefined);
+    this.top = newNode;
   }
 
-  pop(): number | undefined {
-    throw new Error('Not implemented');
+  pop(): number {
+    if (this.isEmpty()) {
+      throw new Error('Stack Underflow: Cannot pop from an empty stack');
+    }
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    const poppedValue = this.top!.val; 
+    this.top = this.top?.next ?? null; 
+    return poppedValue;
   }
 
-  peek(): number | null {
-    throw new Error('Not implemented');
+  peek(): number {
+    if (this.isEmpty()) {
+      throw new Error('Stack is empty: Cannot peek');
+    }
+    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+    return this.top!.val;
   }
 
   isEmpty(): boolean {
-    throw new Error('Not implemented');
+    return this.top === null;
   }
-}
+}