reverse linked list solution

Author: hyer0705

reverse-linked-list/hyer0705.ts

@@ -0,0 +1,27 @@
+/**
+ * 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 reverseList(head: ListNode | null): ListNode | null {
+  if (!head) return null;
+
+  let prev: ListNode | null = null;
+  let current = head;
+
+  while (current) {
+    const temp: ListNode | null = current.next;
+    current.next = prev;
+    prev = current;
+    current = temp;
+  }
+
+  return prev;
+}