Feat: Lesson_12 extra credit: typescript implementations added - James Capparell

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

@@ -2,11 +2,59 @@
 
 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 score_even = 0;
+    int score_odd = 0;
+    int evenNum = 0;
+    int oddNum = 0;
+    for (int i = 0; i < getLength(head); i++) {
+      if (i % 2 == 0) {
+        ListNode resultNode = getElementAt(head, i);
+        evenNum = resultNode.val;
+      } else if (i % 2 == 1) {
+        ListNode resultNode = getElementAt(head, i);
+        oddNum = resultNode.val;
+        if (evenNum > oddNum) {
+          score_even += 1;
+        } else if (evenNum < oddNum) {
+          score_odd += 1;
+        }
+      }
+    }
+    if (score_even > score_odd) {
+      return "Even";
+    } else if (score_even < score_odd) {
+      return "Odd";
+    } else {
+      return "Tie";
+    }
+  }
+
+  public ListNode getElementAt(ListNode head, int position) {
+    ListNode current = head;
+    int index = 0;
+
+    // Traverse the list until reaching the desired position
+    while (current != null) {
+      if (index == position) {
+        return current; // Return the node at the specified position
+      }
+      current = current.next; // Move to the next node
+      index++; // Increment the index
+    }
+
+    return null; // Return null if the position is out of bounds
+  }
+
+  public int getLength(ListNode head) {
+    int length = 0;
+    ListNode current = head;
+
+    while (current != null) {
+      length++; // increment to keep count through each element
+      current = current.next; // moves on to next element
+    }
+
+    return length;
   }
 }

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

@@ -9,18 +9,27 @@ public Stack() {
   }
 
   public void push(int value) {
-    // Your code here
+    ListNode newNode = new ListNode(value, top);
+    top = newNode;
   }
 
   public int pop() {
-    return 0;
+    if (isEmpty()) {
+      throw new IllegalStateException("Stack is empty");
+    }
+    int value = top.val;
+    top = top.next;
+    return value;
   }
 
   public int peek() {
-    return 0;
+    if (isEmpty()) {
+      throw new IllegalStateException("Stack is empty");
+    }
+    return top.val;
   }
 
   public boolean isEmpty() {
-    return true;
+    return top == null;
   }
 }

lesson_12/structs_ts/src/lesson12.ts

@@ -1,11 +1,37 @@
 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 '';
+    let scoreEven = 0;
+    let scoreOdd = 0;
+    let current: ListNode | null = head;
+    let index = 0;
+
+    while (current !== null) {
+      // Check if the index is even
+      if (index % 2 === 0) {
+        // Only check nextNode if current is not the last node
+        const nextNode = current.next;
+        if (nextNode != undefined) {
+          if (current.val > nextNode.val) {
+            scoreEven += 1;
+          } else if (current.val < nextNode.val) {
+            scoreOdd += 1;
+          }
+        }
+      }
+
+      // Move to the next node
+      current = current.next ?? null;
+      index++; // Increment the index
+    }
+
+    if (scoreEven > scoreOdd) {
+      return 'Even';
+    } else if (scoreEven < scoreOdd) {
+      return 'Odd';
+    } else {
+      return 'Tie';
+    }
   }
 }

lesson_12/structs_ts/src/stack.ts

@@ -1,25 +1,34 @@
 import { ListNode } from './list_node.js';
 
 export class Stack {
-  private top: ListNode | undefined;
+  private top?: ListNode;
 
   constructor() {
     this.top = undefined;
   }
 
   push(value: number): void {
-    throw new Error('Not implemented');
+    const newNode = new ListNode(value, this.top);
+    this.top = newNode;
   }
 
   pop(): number | undefined {
-    throw new Error('Not implemented');
+    if (this.isEmpty()) {
+      throw new Error('Stack is empty');
+    }
+    const value = this.top?.val; // Non-null assertion since we've checked for emptiness
+    this.top = this.top?.next; // No change needed here, TypeScript allows accessing next
+    return value;
   }
 
-  peek(): number | null {
-    throw new Error('Not implemented');
+  peek(): number | undefined {
+    if (this.isEmpty()) {
+      throw new Error('Stack is empty');
+    }
+    return this.top?.val; // Non-null assertion since we've checked for emptiness
   }
 
   isEmpty(): boolean {
-    throw new Error('Not implemented');
+    return this.top === undefined; // Check for undefined since top is optional
   }
 }