feat: Reverse Linked List #223

Author: donghyeon95

reverse-linked-list/donghyeon95.java

@@ -0,0 +1,28 @@
+/**
+ * Definition for singly-linked list.
+ * public class ListNode {
+ *     int val;
+ *     ListNode next;
+ *     ListNode() {}
+ *     ListNode(int val) { this.val = val; }
+ *     ListNode(int val, ListNode next) { this.val = val; this.next = next; }
+ * }
+ */
+
+// 시간 복잡도 : O(n)
+// 공간 복잡도 : O(n)
+class Solution {
+	public ListNode reverseList(ListNode head) {
+		// 반복문을 돌면서 f(x+1)의 next를 f(x)로 지정
+		ListNode result = null;
+
+		while(head != null) {
+			ListNode nextNode = new ListNode(head.val);
+			nextNode.next = result;
+			result = nextNode;
+			head = head.next;
+		}
+
+		return result;
+	}
+}