Create Rotate List.cpp

Author: daizhenyang

Rotate List.cpp

@@ -0,0 +1,41 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode(int x) : val(x), next(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    ListNode *rotateRight(ListNode *head, int k) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        ListNode *ptr=head,*pre;
+        int len=0;
+        while (ptr)
+        {
+            ++len;
+            ptr=ptr->next;
+        }
+        if (!len)return head;
+        k%=len;
+        if (!k)return head;
+        int c=len-k;
+        pre=ptr=head;
+        while (c--)
+        {
+            pre=ptr;
+            ptr=ptr->next;
+        }
+        pre->next=NULL;
+        ListNode *ed=ptr;
+        while (ed)
+        {
+            pre=ed;
+            ed=ed->next;
+        }
+        pre->next=head;
+        return ptr;
+    }
+};