Merge pull request PawanJaiswal08#28 from Vartika-Kulshreshtha/rotate-list

Create 61. Rotate List

Author: PawanJaiswal08

61. Rotate List

@@ -0,0 +1,36 @@
+/**
+ * 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:
+    ListNode* rotateRight(ListNode* head, int k) {
+        ListNode* curr = head;
+        int len = 1;
+        
+        while(head == NULL || head -> next == NULL || k==0)
+            return head;
+        while(curr -> next != NULL)
+        {
+            len++;
+            curr = curr -> next;
+        }
+        curr -> next = head;
+        k = k % len;
+        k = len - k;
+        while(k-- > 0)
+        {
+            curr = curr -> next;
+        }
+        head = curr -> next;
+        curr -> next = NULL;
+        
+        return head;
+    }
+};