merge-two-sorted-lists solution(py, ts)

Author: hi-rachel

merge-two-sorted-lists/hi-rachel.py

@@ -0,0 +1,33 @@
+# O(n + m) time, n = list1의 노드 수 / m = list2의 노드 수
+# O(1) space, 연결된 새 리스트는 기존 노드들을 재사용해서 만듬
+
+# Definition for singly-linked list.
+# class ListNode:
+#     def __init__(self, val=0, next=None):
+#         self.val = val
+#         self.next = next
+
+class ListNode:
+    def __init__(self, val=0, next=None):
+        self.val = val
+        self.next = next
+
+class Solution:
+    def mergeTwoLists(self, list1: Optional[ListNode], list2: Optional[ListNode]) -> Optional[ListNode]:
+        dummy = ListNode()
+        tail = dummy
+
+        while list1 and list2:
+            if list1.val < list2.val:
+                tail.next = list1
+                list1 = list1.next
+            else:
+                tail.next = list2
+                list2 = list2.next
+            tail = tail.next
+
+        if list1:
+            tail.next = list1
+        if list2:
+            tail.next = list2
+        return dummy.next

merge-two-sorted-lists/hi-rachel.ts

@@ -0,0 +1,45 @@
+/**
+ * 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)
+ *     }
+ * }
+ */
+
+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 mergeTwoLists(
+  list1: ListNode | null,
+  list2: ListNode | null
+): ListNode | null {
+  const dummy = new ListNode();
+  let tail = dummy;
+  while (list1 !== null && list2 !== null) {
+    if (list1.val < list2.val) {
+      tail.next = list1;
+      list1 = list1.next;
+    } else {
+      tail.next = list2;
+      list2 = list2.next;
+    }
+    tail = tail.next;
+  }
+  if (list1 !== null) {
+    tail.next = list1;
+  }
+  if (list2 !== null) {
+    tail.next = list2;
+  }
+  return dummy.next;
+}