From 400defd81281c8feb267beeff31e394e4fc8559c Mon Sep 17 00:00:00 2001
From: Gabriel Donnan <47415809+gabedonnan@users.noreply.github.com>
Date: Thu, 30 Mar 2023 12:07:48 +0100
Subject: [PATCH] Create rotate-list.cpp

beats 96.7
---
 rotate-list.cpp | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 rotate-list.cpp

diff --git a/rotate-list.cpp b/rotate-list.cpp
new file mode 100644
index 0000000..1cde01c
--- /dev/null
+++ b/rotate-list.cpp
@@ -0,0 +1,47 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode() : val(0), next(nullptr) {}
+ *     ListNode(int x) : val(x), next(nullptr) {}
+ *     ListNode(int x, ListNode *next) : val(x), next(next) {}
+ * };
+ */
+class Solution {
+public:
+    int getListLength(ListNode* curr) {
+        int fin = 0;
+        while (curr != NULL) {
+            fin++;
+            curr = curr->next;
+        }
+        return fin;
+    }
+
+    ListNode* rotateRight(ListNode* head, int k) {
+        int len = getListLength(head);
+        if (len == 0) {
+            return head;
+        }
+        k = k % len;
+        if (k == 0) {
+            return head;
+        }
+
+        ListNode* secondHalfTail = head;
+        for (int i = 0; i < (len - 1) - k; i++) {
+            secondHalfTail = secondHalfTail->next;
+        }
+        
+
+        ListNode* firstHalfHead = secondHalfTail->next;
+        ListNode* finalVal = firstHalfHead;
+        secondHalfTail->next = NULL;
+        while (firstHalfHead->next != NULL) {
+            firstHalfHead = firstHalfHead->next;
+        }
+        firstHalfHead->next = head;
+        return finalVal;
+    }
+};