uva 101 - The Blocks Problem -solution

#include <cstdio>
#include <cstring>
#include <string>
#include <stack>
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 c1[10], c2[10];

        while(scanf("%d",&n)==1)
        {
                for(int i = 0; i < n; i++)
                {
                        s[i].push(i);
                        block[i] = i;
                }

                while(scanf("%s",c1)!=EOF)
                {
                         if(c1[0] == 'q')
                                 break;

                         scanf("%d %s %d",&a,c2,&b);

                         if(a != b && block[a] != block[b])
                         {
                                 if(c1[0] == 'm')
                                 {
                                         if(c2[1] == 'n')
                                                 move_onto(a,b);
                                         else
                                                 move_over(a,b);
                                 }
                                 else
                                 {
                                          if(c2[1] == 'n')
                                                  pile_onto(a,b);
                                          else
                                                  pile_over(a,b);
                                  }
                         }
               }

                for(int i = 0; i < n; i++)
               {
                       printf("%d:",i);
                       while(!s[i].empty())
                       {
                                tmp.push(s[i].top());
                                s[i].pop();
                        }

                        while(!tmp.empty())
                        {
                                printf(" %d",tmp.top());
                                tmp.pop();
                        }
                        printf("\n");
                 }
        }
        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();
        }
}