연결리스트 뒤집기

Author: holmir97

ReverseLinkedList/ListNode.java

@@ -0,0 +1,16 @@
+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;
+    }
+}

ReverseLinkedList/ReverseLinkedList.java

@@ -0,0 +1,26 @@
+
+public class ReverseLinkedList {
+
+    public ListNode reverseList(ListNode head) {
+        ListNode prev = null;
+        ListNode curr = head;
+        while (curr != null) {
+            ListNode nextTemp = curr.next;
+            curr.next = prev;
+            prev = curr;
+            curr = nextTemp;
+        }
+        return prev;
+    }
+}
+
+/* USE_recursive
+public ListNode reverseList(ListNode head) {
+    if (head == null || head.next == null) return head;
+    ListNode p = reverseList(head.next);
+    head.next.next = head;
+    head.next = null;
+    return p;
+}
+
+ */