✨ [206] Reverse Linked List

Runtime 60 ms Beats 77.47% Memory 43.7 MB Beats 95.22%

Author: enkr1

206/my_solution.js

@@ -0,0 +1,27 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+class ListNode {
+  constructor(val, next) {
+    this.val = (val === undefined ? 0 : val);
+    this.next = (next === undefined ? null : next);
+  }
+}
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const reverseList = (head) => {
+  let dummy = new ListNode(), new_head = dummy;
+
+  while (head !== null) {
+    dummy.next = new ListNode(head.val, dummy.next);
+    head = head.next;
+  }
+
+  return new_head.next;
+};

206/solution.js

@@ -0,0 +1,29 @@
+/**
+ * Definition for singly-linked list.
+ * function ListNode(val, next) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.next = (next===undefined ? null : next)
+ * }
+ */
+/**
+ * @param {ListNode} head
+ * @return {ListNode}
+ */
+const reverseList = (head) => {
+  let dummy = new ListNode(), new_head = dummy;
+
+  while (head !== null) {
+    dummy.next = new ListNode(head.val, dummy.next);
+    head = head.next;
+
+    console.log("dummy")
+    console.log(dummy)
+    console.log("dummy.next")
+    console.log(dummy.next)
+    // dummy = dummy.next;
+  }
+
+  return new_head.next;
+};
+
+reverseList(new ListNode(1, new ListNode(2, new ListNode(3, new ListNode(4, new ListNode(5))))))

README.md

@@ -28,6 +28,7 @@
 - [191. Number of 1 Bits](./191/)
 - [198. House Robber](./198/)
 - [200. Number of Islands](./200/)
+- [206. Reverse Linked List](./206/)
 - [213. House Robber II](./213/)
 - [217. Contains Duplicate](./217/)
 - [238. Product of Array Except Self](./238/)
@@ -61,10 +62,11 @@ iex ./.../solution.ex
 
 ---
 
-Quick create in bash
+Batch create in bash
 ```ssh
-chapter=21 && mkdir ./$chapter && touch ./$chapter/my_solution.js && touch ./$chapter/solution.js && alias x="node ./$chapter/my_solution.js"
+chapter=206 && mkdir ./$chapter && touch ./$chapter/my_solution.js && touch ./$chapter/solution.js && alias x="node ./$chapter/my_solution.js"
 ```
+> And now you can use `x` for quick debug.
 
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