ACM - UVA 101 - The blocks problem

http://www.algorithmist.com/index.php/UVa_101The problem:101 - The Blocks Problem
The solution: C++
Hints: http://www.algorithmist.com/index.php/UVa_101

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <string>
#include <cctype>
#include <stack>
#include <queue>
#include <list>
#include <vector>
#include <map>
#include <sstream>
#include <utility>
#include <set>
#include <math.h>
using namespace std;

int block[25];

stack<int> s[25], tmp;

void move_onto(int a, int b);
void move_over(int a, int b);
void pile_onto(int a, int b);
void pile_over(int a, int b);

int main()
{
        int n, a, b;
        char ar_1[10], ar_2[10];

        while(cin >> n) 
        {
                for(int i = 0; i < n; i++)
                {
                        s[i].push(i);
                        block[i] = i;
                }

                while(cin >> ar_1)
                {
                         if(ar_1[0] == 'q')
                                 break;

                         cin >> a >> ar_2 >> b;

                         if(a != b && block[a] != block[b])
                         {
                                 if(ar_1[0] == 'm')
                                 {
                                         if(ar_2[1] == 'n')
                                                 move_onto(a,b);
                                         else
                                                 move_over(a,b);
                                 }
                                 else
                                 {
                                          if(ar_2[1] == 'n')
                                                  pile_onto(a,b);
                                          else
                                                  pile_over(a,b);
                                  }
                         }
               }

                for(int i = 0; i < n; i++)
               {
                       cout << i << ":";
                       if(s[i].empty())
                               cout << endl;
                       else
                       { 
                               while(!s[i].empty())
                               {
                                       tmp.push(s[i].top());
                                       s[i].pop();
                                }

                                 while(!tmp.empty())
                                 {
                                          cout << " " << tmp.top();
                                          tmp.pop();
                                  }
                                  cout << endl;
                         }
                 }
        }
        return 0;
}

void move_onto(int a, int b)
{
        while(s[block[a]].top() != a)
        {
                int t = s[block[a]].top();
                s[t].push(t);
                block[t] = t;
                s[block[a]].pop();
        }

        while(s[block[b]].top() != b)
        {
                int t = s[block[b]].top();
                s[t].push(t);
                block[t] = t;
                s[block[b]].pop();
        }

        s[block[b]].pop();
        block[b] = b;
        s[b].push(b);

        s[b].push(s[block[a]].top());
        s[block[a]].pop();
        block[a] = b;
}

void move_over(int a, int b)
{
        while(s[block[a]].top() != a)
        {
                int t = s[block[a]].top();
                s[t].push(t);
                block[t] = t;
                s[block[a]].pop();
        }

        s[block[b]].push(s[block[a]].top());
        s[block[a]].pop();
        block[a] = block[b];
}

void pile_onto(int a, int b)
{
        while(s[block[b]].top() != b)
        {
                 int t = s[block[b]].top();
                 s[t].push(t);
                 block[t] = t;
                 s[block[b]].pop();
         }

          s[block[b]].pop();
          block[b] = b;
          s[b].push(b);

          while(s[block[a]].top() != a)
          {
                  tmp.push(s[block[a]].top());
                  s[block[a]].pop();
          }

          tmp.push(s[block[a]].top());
          s[block[a]].pop();

          while(!tmp.empty())
          {
                  s[block[b]].push(tmp.top());
                  block[tmp.top()] = block[b];
                  tmp.pop();
          }
}

void pile_over(int a, int b)
{
        while(s[block[a]].top() != a)
        {
                tmp.push(s[block[a]].top());
                s[block[a]].pop();
        }

        tmp.push(s[block[a]].top());
        s[block[a]].pop();

        while(!tmp.empty())
        {
                s[block[b]].push(tmp.top());
                block[tmp.top()] = block[b];
                tmp.pop();
        }
}