Given the C++ code: // toh.cpp #include #include using namespace std; int main() {     vector t[3];     int n;     cout << "Enter the number of rings: ";     cin >> n;     int from = 0;     int candidate = 1;     int to, move = 0;     if ( n % 2 == 0)     to = 2;   // (from + to)%mod3, counter clockwise     else         to = 1;  // (from + to)%mod3, clockwise     for ( int i =  n + 1 ; i >= 1; i-- )         t[0].push_back(i);       t[1].push_back(n+1);       t[2].push_back(n+1);     if ( n % 2  ==  0 )     {       while ( t[1].size() < (n+1) ) {           cout << "move " << ++move << ":" << " Move candidate " << candidate;           cout << " from tower " << (char) (from + 'A');           cout << " to tower " << (char)(to + 'A') << endl;           t[to].push_back(t[from].back());           t[from].pop_back();           if (t[(to+2)%3].back() < t[(to+1)%3].back())               from = (to + 2)%3;           else               from = (to + 1)%3;           if (t[(from)%3].back() < t[(from+2)%3].back())               to = (from + 2)%3;           else               to = (from + 1)%3;           candidate = t[from].back();         }         return 0;     } else {       while ( t[1].size() < ( n+1 )   ) {           cout << "move " << ++move << ":" << " Move candidate " << candidate;           cout << " from tower " << (char) (from + 'A');           cout << " to tower " << (char)(to + 'A') << endl;           t[to].push_back(t[from].back());           t[from].pop_back();           if (t[(to+1)%3].back() < t[(to+2)%3].back())               from = ( to + 1 )%3;           else               from = ( to + 2 )%3;           //cout << "from = " << from << endl;           if (t[(from)%3].back()  <  t[(from+1)%3].back())               to = (from + 1)%3;           else               to = (from + 2)%3;           //cout << "to = " << to <

Given the C++ code:

// toh.cpp
#include <iostream>
#include <vector>
using namespace std;

int main() {
    vector<int> t[3];
    int n;
    cout << "Enter the number of rings: ";
    cin >> n;
    int from = 0;
    int candidate = 1;
    int to, move = 0;

    if ( n % 2 == 0)
    to = 2;   // (from + to)%mod3, counter clockwise
    else
        to = 1;  // (from + to)%mod3, clockwise

    for ( int i =  n + 1 ; i >= 1; i-- )
        t[0].push_back(i);
      t[1].push_back(n+1);
      t[2].push_back(n+1);

    if ( n % 2  ==  0 )
    {

      while ( t[1].size() < (n+1) ) {

          cout << "move " << ++move << ":" << " Move candidate " << candidate;
          cout << " from tower " << (char) (from + 'A');
          cout << " to tower " << (char)(to + 'A') << endl;

          t[to].push_back(t[from].back());
          t[from].pop_back();
          if (t[(to+2)%3].back() < t[(to+1)%3].back())
              from = (to + 2)%3;
          else
              from = (to + 1)%3;

          if (t[(from)%3].back() < t[(from+2)%3].back())
              to = (from + 2)%3;
          else
              to = (from + 1)%3;
          candidate = t[from].back();
        }
        return 0;

    } else {

      while ( t[1].size() < ( n+1 )   ) {
          cout << "move " << ++move << ":" << " Move candidate " << candidate;
          cout << " from tower " << (char) (from + 'A');
          cout << " to tower " << (char)(to + 'A') << endl;
          t[to].push_back(t[from].back());
          t[from].pop_back();
          if (t[(to+1)%3].back() < t[(to+2)%3].back())
              from = ( to + 1 )%3;
          else
              from = ( to + 2 )%3;
          //cout << "from = " << from << endl;
          if (t[(from)%3].back()  <  t[(from+1)%3].back())
              to = (from + 1)%3;
          else
              to = (from + 2)%3;
          //cout << "to = " << to <<endl;

          candidate = t[from].back();
        }
        return 0;
    }

    return 0;
}

Questions:

1. What will be the first from and to towers, given that there is an odd (not even) number of rings?
2. Once the towers are initialized, what rings will be on towers 1, 2, and 3?