Create Remove Nth Node From End of List.cpp

Author: daizhenyang

Remove Nth Node From End of List.cpp

@@ -0,0 +1,35 @@
+/**
+ * Definition for singly-linked list.
+ * struct ListNode {
+ *     int val;
+ *     ListNode *next;
+ *     ListNode(int x) : val(x), next(NULL) {}
+ * };
+ */
+class Solution {
+public:
+    ListNode *removeNthFromEnd(ListNode *head, int n) {
+        // Start typing your C/C++ solution below
+        // DO NOT write int main() function
+        ListNode *p1=head,*p2=head,*pre;
+        int c=n;
+        while (c--)p2=p2->next;
+        if (!p2)
+        {
+            ListNode *tmp=head;
+            head=head->next;
+            delete tmp;
+            return head;
+        }
+        while (p2)
+        {
+            pre=p1;
+            p1=p1->next;
+            p2=p2->next;
+        }
+        ListNode *tmp=p1;
+        pre->next=p1->next;
+        delete tmp;
+        return head;
+    }
+};