Add merge-k-sorted-lists solution in TS

Author: Jeehay28

merge-k-sorted-lists/Jeehay28.ts

@@ -0,0 +1,37 @@
+class ListNode {
+  val: number;
+  next: ListNode | null;
+  constructor(val?: number, next?: ListNode | null) {
+    this.val = val === undefined ? 0 : val;
+    this.next = next === undefined ? null : next;
+  }
+}
+
+// TC: O(n * log n), n = total number of all nodes combined (across all lists)
+// SC: O(n)
+// TDDO: Implement more optimized solution using Min Heap with TC: O(n log k)
+function mergeKLists(lists: Array<ListNode | null>): ListNode | null {
+  const nodeValues: number[] = [];
+
+  for (let node of lists) {
+    while (node) {
+      nodeValues.push(node.val);
+      node = node.next;
+    }
+  }
+
+  nodeValues.sort((a, b) => a - b);
+
+  if (nodeValues.length === 0) return null;
+
+  const head = new ListNode(nodeValues[0]);
+  let temp = head;
+
+  for (let i = 1; i < nodeValues.length; i++) {
+    temp.next = new ListNode(nodeValues[i]);
+    temp = temp.next;
+  }
+
+  return head;
+}
+