Data Structure Linked List: Write a function to reverse a linked list

 1 #include <iostream>
 2 #include <vector>
 3 #include <algorithm>
 4 #include <queue>
 5 #include <stack>
 6 #include <string>
 7 #include <fstream>
 8 #include <map>
 9 #include <set>
10 using namespace std;
11 
12 struct node {
13     int data;
14     node *next;
15     node() : data(0), next(NULL) { }
16     node(int d) : data(d), next(NULL) { }
17 };
18 
19 void push(node* &head, int k) {
20     node *new_node = new node(k);
21     new_node->next = head;
22     head = new_node;
23 }
24 
25 void print(node *head) {
26     while (head) {
27         cout << head->data << " ";
28         head = head->next;
29     }
30     cout << endl;
31 }
32 
33 void reverselist(node *&head) {
34     if (!head) return;
35     node *cur = head;
36     node *next = head->next;
37     if (!next) return;
38     reverselist(next);
39     cur->next->next = cur;
40     cur->next = NULL;
41     head = next;
42 }
43 
44 int main() {
45     node *head = NULL;
46     push(head, 5);
47     push(head, 4);
48     push(head, 3);
49     push(head, 2);
50     push(head, 1);
51     print(head);
52     reverselist(head);
53     print(head);
54     return 0;
55 }