CPS 6 Test 2 Solutions
Prof. Rodger
Fall 2000

Problem 1 

Mystery(3)
1 3 2
Something(-12)
-12 -7 -2 1

Problem 2 - Part A

int NumSolved(const tmatrix<int> & teams, int row)
// pre: all entries in teams are 0 or 1, 1 indicates the problem was solved
// post: returns the number of problems solved by the team in row
{
   int k;
   int count = 0;
   for (k=0; k<teams.numcols(); k++)
   {
      if (teams[row][k] > 0)
        count ++;
   }
   return count;
}

Problem 2 - Part B

int MaxNumSolved(const tmatrix<int> & teams)
// post: Returns the maximum number of problems solved by a team
{
   int j, cnt, maxcnt;
   maxcnt = 0;;
   for (j=0; j<teams.numrows(); j++)
   {
      cnt = NumSolved(teams,j);
      if (cnt > maxcnt)
      {
           maxcnt = cnt;
      }
   }
   return maxcnt;
}

Problem 3 - Part A

Poll::Poll()
  : myStudents(0), myNumStudents(0)
{
}

Problem 3 - Part B

void Poll::ReadIn()
// post: reads in data into myStudents. For each student puts in 
// the candidates name (one word) and the first and last name only
// of the student. Updates myNumStudents.
{
  Person temp;
  string line;
  while (getline(cin, line))
  {
    istrstream input(line.c_str());
    input >> temp.cand;
    input >> temp.first;
    while (input >> temp.last)
    {  // empty
    }
    myStudents.push_back(temp);
  }
  myNumStudents = myStudents.size();
}

Problem 3 - Part C

int Poll::Count(const string & name)
// post: returns the number of votes for name
{
  int num = 0;
  int k;
  for (k=0; k<myStudents.size(); k++)
  {
       if (myStudents[k].cand == name)
           num++;
  }
  return num;
}

Problem 3 - Part D

bool Poll::IsCandidate(const tvector<string> &  allnames, const string & name)
// post: returns true if name appears in allnames, otherwise returns false
{
   int k;
   for (k=0; k<allnames.size(); k++)
   {
      if (allnames[k] == name)
         return true;
   }
   return false;
}   

Problem 3 - Part E

tvector<string> Poll::Candidates()
// post: returns an array of candidate names, one entry per candidate,
// the array contains size() entries
{
   int k;
   tvector <string> temp;
   for (k = 0; k<myStudents.size(); k++)
   {
       if (!IsCandidate(temp, myStudents[k].cand))
           temp.push_back(myStudents[k].cand);
   }
   return temp;
}