feat: 206. Reverse Linked List

Author: gwbaik9717

reverse-linked-list/gwbaik9717.js

@@ -0,0 +1,40 @@
+// Time complexity: O(n)
+// Space complexity: O(n)
+
+/**
+ * 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}
+ */
+var reverseList = function (head) {
+  const stack = [];
+
+  let temp = head;
+  while (temp) {
+    stack.push(temp.val);
+    temp = temp.next;
+  }
+
+  if (!stack.length) {
+    return null;
+  }
+
+  const popped = stack.pop();
+  const answer = new ListNode(popped);
+
+  temp = answer;
+  while (stack.length > 0) {
+    const popped = stack.pop();
+
+    temp.next = new ListNode(popped);
+    temp = temp.next;
+  }
+
+  return answer;
+};