feat: Upload merge-k-sorted-lists (typescript)

merge-k-sorted-lists/mike2ox.ts

@@ -0,0 +1,48 @@
+/**
+ * Source: https://leetcode.com/problems/merge-k-sorted-lists/
+ * 풀이방법: 모든 리스트들을 한곳에 넣고 재배치
+ *
+ * 시간복잡도: O(NlogN) - 모든 리스트를 순회(N), 정렬(NlogN) 하는데 드는 시간 고려
+ * 공간복잡도: O(N) - 기존 배열을 저장할 공간만 필요
+ */
+
+/**
+ * Definition for singly-linked list.
+ * 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)
+ *     }
+ * }
+ */
+
+function mergeKLists(lists: Array<ListNode | null>): ListNode | null {
+  if (!lists?.length) return null;
+  let merged = [];
+
+  for (let i = 0; i < lists.length; i++) {
+    let cursor = lists[i];
+    while (cursor != null) {
+      merged.push(cursor.val);
+      cursor = cursor.next;
+    }
+  }
+  let sorted = merged.sort((a, b) => (a < b ? -1 : 1));
+  let head = null;
+  let tail = null;
+
+  for (let i = 0; i < sorted.length; i++) {
+    const node = new ListNode(sorted[i], null);
+    if (head === null) {
+      head = node;
+      tail = node;
+    } else {
+      tail.next = node;
+      tail = node;
+    }
+  }
+
+  return head;
+}