Data Structure Stack: Reverse a stack using recursion

http://www.geeksforgeeks.org/reverse-a-stack-using-recursion/

 #include <iostream>
 #include <vector>
 #include <algorithm>
 #include <queue>
 #include <stack>
 #include <string>
 #include <fstream>
 #include <map>
 #include <set>
 using namespace std;
 
 void insertbottom(stack<int> &S, int top) {
     if (S.empty()) S.push(top);
     else {
         int tmp = S.top();
         S.pop();
         insertbottom(S, top);
         S.push(tmp);
     }
 }
 
 void reversestack(stack<int> &S) {
     if (S.empty()) return;
     int top = S.top();
     S.pop();
     reversestack(S);
     insertbottom(S, top);
 }
 
 int main() {
     stack<int> S;
     S.push();
     S.push();
     S.push();
     S.push();
     reversestack(S);
     while (!S.empty()) {
         cout << S.top() << endl;
         S.pop();
     }
     return ;
 }