added deleteMiddle & oddEvenList

Author: shkvik

src/linked_list/delete-middle.ts

@@ -0,0 +1,63 @@
+import { ListNode } from "./linked_list.structure";
+import { createLinkedList, linkedListToArray } from "./utilities";
+
+/**
+ * @problem 
+ * [2095. Delete the Middle Node of a Linked List](https://leetcode.com/problems/delete-the-middle-node-of-a-linked-list)
+ */
+function deleteMiddle(head: ListNode | null): ListNode | null {
+  var slow = head;
+  var fast = head;
+  var prev = null;
+
+  if (!head || !head.next) {
+    return null;
+  }
+  while (fast && fast.next) {
+    fast = fast.next.next;
+    prev = slow;
+    slow = slow.next;
+  }
+
+  prev.next = slow.next;
+
+  return head;
+};
+
+export function deleteMiddleDBG() {
+  const tests = [
+    {
+      input: createLinkedList([1, 3, 4, 7, 1, 2, 6]),
+      result: [1, 3, 4, 1, 2, 6]
+    },
+    {
+      input: createLinkedList([1, 2, 3, 4]),
+      result: [1, 2, 4]
+    },
+    {
+      input: createLinkedList([2, 1]),
+      result: [2]
+    },
+    {
+      input: createLinkedList([1]),
+      result: []
+    },
+    {
+      input: createLinkedList([]),
+      result: []
+    }
+  ];
+
+  tests.forEach((test, index) => {
+    const output = deleteMiddle(test.input);
+    const outputArray = linkedListToArray(output);
+    const success = JSON.stringify(outputArray) === JSON.stringify(test.result);
+    if (success) {
+      console.log(`${index} success`);
+    } else {
+      console.log(`${index} fail`);
+      console.log(`expected ${JSON.stringify(test.result)}`);
+      console.log(`got ${JSON.stringify(outputArray)}`);
+    }
+  });
+}

src/linked_list/odd-even-list.ts

@@ -0,0 +1,65 @@
+import { ListNode } from "./linked_list.structure";
+import { createLinkedList, linkedListToArray } from "./utilities";
+
+/**
+ * @problem 
+ * [328. Odd Even Linked List](https://leetcode.com/problems/odd-even-linked-list)
+ */
+function oddEvenList(head: ListNode | null): ListNode | null {
+  if (!head) {
+    return null;
+  }
+  if (!head.next) {
+    return head;
+  }
+  let odd = head;
+  let even = head.next;
+  let evenHead = even;
+
+  while (even && even.next) {
+    odd.next = even.next;
+    odd = odd.next;
+    even.next = odd.next;
+    even = even.next;
+  }
+  odd.next = evenHead;
+  return head;
+};
+
+export function oddEvenListDBG() {
+  const tests = [
+    {
+      input: createLinkedList([1, 2, 3, 4, 5]),
+      result: [1, 3, 5, 2, 4]
+    },
+    {
+      input: createLinkedList([2, 1, 3, 5, 6, 4, 7]),
+      result: [2, 3, 6, 7, 1, 5, 4]
+    },
+    {
+      input: createLinkedList([]),
+      result: []
+    },
+    {
+      input: createLinkedList([1]),
+      result: [1]
+    },
+    {
+      input: createLinkedList([1, 2]),
+      result: [1, 2]
+    }
+  ];
+
+  tests.forEach((test, index) => {
+    const oddEven = oddEvenList(test.input);
+    const resultArray = linkedListToArray(oddEven);
+    const success = JSON.stringify(resultArray) === JSON.stringify(test.result);
+    if (success) {
+      console.log(`${index} success`);
+    } else {
+      console.log(`${index} fail`);
+      console.log(`expected ${JSON.stringify(test.result)}`);
+      console.log(`got ${JSON.stringify(resultArray)}`);
+    }
+  });
+}

src/main.ts

@@ -1,3 +1,4 @@
-import { dota2SenateDBG } from "./queue/predict-party-victory";
+import { deleteMiddleDBG } from "./linked_list/delete-middle";
+import { oddEvenListDBG } from "./linked_list/odd-even-list";
 
-dota2SenateDBG()
+oddEvenListDBG()