Still celebrating National IT Professionals Day with 3 months of free Premium Membership. Use Code ITDAY17

x
?
Solved

How do you use 2D vectors in functions???

Posted on 2004-04-28
6
Medium Priority
?
200 Views
Last Modified: 2013-12-14
I'm writing a class right now and I have a little problem.

How do you use two dimensional vectors in functions?

I have this function named "mark" which takes in a char and returns a 2D vector.
How do you write it in a header file???

My guess is:

vector mark(char);

or

vector<vector> mark(char);

or

vector<vector<int> > mark(char);

HELP!!
0
Comment
Question by:vanhowen
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
6 Comments
 
LVL 40

Accepted Solution

by:
Kyle Abrahams earned 750 total points
ID: 10944716
try

vector<int> *

or, create the 2D vector before hand, and pass it down as a reference

IE:

void mark (char, vector< vector<int> > &);
0
 
LVL 86

Assisted Solution

by:jkr
jkr earned 750 total points
ID: 10944908
As I showed you in http://www.experts-exchange.com:8080/Programming/Programming_Languages/Cplusplus/Q_20970981.html and ged325 clarifieded: Use references - like with the function

void ReadValues ( string& s, vector<int>& v) {

    // ...
}

I used in the other Q, you should pass the vector as a parameter to avoid overhead. But, since this is the C++ area and therefor an OO thing: Why don't you create a class to handle that, you would not even have to pass the vector of vectors:

class My2DVector {

public:

// the usual stuff...

void mark(char) {

    //...

    // you can use m_data directly here without having to pass it
}

protected:

vector<vector<int> > m_data;

};
0
 
LVL 4

Expert Comment

by:PerryDK
ID: 10946106
I think you will find my previous post in other thread enough to answer both questions.  Here is the entire post again so that you can get a feal for an entire project

Your lucky I'm interested in games...here is what I have done so far.  You will have to add code to check to see if the game is complete and also display output when the user selcted a bomb.

When you get it finished I'd like to see the final code.  If I get more time I may finish writing the program.
BTW what compiler are you using...do you want to make this a graphical game?


PARTIAL OUTPUT
MineSweeperGrid
5 6
1 0 1 0 1 0
0 0 0 0 1 0
0 0 0 1 0 0
0 1 0 0 0 0
1 0 0 0 0 0

DisplayGrid:
UUUUUU
UUUUUU
UUUUUU
UUUUUU
UUUUUU
Enter a grid a point to select: 4 4
DisplayGrid:
UUUUUU
UUUUUU
UUUU21
UU111
UU1
Enter a grid a point to select: 1 1
DisplayGrid:
U1UUUU
1 11UU
   U21
 U111
U21
Enter a grid a point to select: 4 4

PROGRAM

#include <iostream>
#include <vector>
#include <fstream>
#include <string>
#include <assert>

using namespace std;

class MineSweeper
{
public:
  typedef vector< vector<int> > MineSweeperGrid;
  typedef vector< vector<char> > MineSweeperDisplay;

  static const char UNKNOWN   = 'U';
  static const char CLEAR     = ' ';
  static const char BOMB      = 'X';

  MineSweeper(const int numRows = 5, const int numCols = 6, const int numMines = 7);
  ~MineSweeper();

  void clear();
  void randomInitialize();
  int getNumRows();
  int getNumCols();
  bool getBombSelected();

  void displayToUser(ostream& os = cout);
  void select(const int row, const int col);

  friend ostream& operator << (ostream& os, const MineSweeper& ms);
  friend istream& operator >> (istream& is, MineSweeper& ms);
protected:
private:
  void resizeGrid();
  void checkSelectedPoint(const int row, const int col);
  int bombsAroundPoint(const int row, const int col);

  int numRows;
  int numCols;
  int numMines;
  bool bombSelected;

  int currentlySelectedRow;
  int currentlySelectedCol;

  MineSweeperGrid grid;
  MineSweeperDisplay displayGrid;
};

MineSweeper::MineSweeper(const int numRows, const int numCols, const int numMines)
{
  assert(numRows > 0);
  assert(numCols > 0);
  assert(numMines >= 0);

  this->numRows = numRows;
  this->numCols = numCols;
  this->numMines = numMines;

  randomInitialize();
}

MineSweeper::~MineSweeper()
{
}

void MineSweeper::clear()
{
  grid.clear();
  resizeGrid();
  bombSelected = false;
}

void MineSweeper::randomInitialize()
{
  assert(numMines <= numRows * numCols);
  clear();

  int currentMines = 0;
  while(currentMines < numMines)
  {
    int r = rand() % numRows;
    int c = rand() % numCols;
    if(grid[r][c] == 0)
    {
      grid[r][c] = 1;
      currentMines++;
    }
  }
}

int MineSweeper::getNumRows()
{
  return numRows;
}

int MineSweeper::getNumCols()
{
  return numCols;
}

bool MineSweeper::getBombSelected()
{
  return bombSelected;
}

void MineSweeper::displayToUser(ostream& os)
{
  for(int r = 0; r < numRows; r++)
  {
    for(int c = 0; c < numCols; c++)
      os << displayGrid[r][c];

    cout << endl;
  }
}

void MineSweeper::select(const int row, const int col)
{
  assert(row >= 0 && row < numRows);
  assert(col >= 0 && col < numCols);

  if(grid[row][col] == 1)
  {
    for(int r = 0; r < numRows; r++)
      for(int c = 0; c < numCols; c++)
        if(grid[r][c] == 1)
          displayGrid[r][c] = BOMB;
        else
          displayGrid[r][c] = CLEAR;

    bombSelected = true;
    return;
  }

  currentlySelectedRow = row;
  currentlySelectedCol = col;
  checkSelectedPoint(row, col);
}

void MineSweeper::checkSelectedPoint(const int row, const int col)
{
  if(currentlySelectedRow == row && currentlySelectedCol == col)
    displayGrid[row][col] = CLEAR;

  bool readyToReturn = true;
  for(int r = row -1; r <= row + 1; r++)
  {
    if(r < 0 || r >= numRows)
      continue;
    for(int c = col -1; c <= col + 1; c++)
    {
      if(c < 0 || c >= numCols)
        continue;

      if(grid[r][c] != 1 && displayGrid[r][c] == UNKNOWN)
        readyToReturn = false;
    }
  }

  if(readyToReturn)
    return;

  if(displayGrid[row][col] != UNKNOWN && displayGrid[row][col] != CLEAR)
    return;



  for(int r = row -1; r <= row + 1; r++)
  {
    if(r < 0 || r >= numRows)
      continue;
    for(int c = col -1; c <= col + 1; c++)
    {
      if(c < 0 || c >= numCols)
        continue;
      if(displayGrid[r][c] == CLEAR)
        continue;
      if(grid[r][c] == 1)
        continue;


      int numBombs = bombsAroundPoint(r, c);
      switch( numBombs )
      {
        case 0:
          displayGrid[r][c] = CLEAR;
          break;
        case 1:
          displayGrid[r][c] = '1';
          break;
        case 2:
          displayGrid[r][c] = '2';
          break;
        case 3:
          displayGrid[r][c] = '3';
          break;
        case 4:
          displayGrid[r][c] = '4';
          break;
        case 5:
          displayGrid[r][c] = '5';
          break;
        case 6:
          displayGrid[r][c] = '6';
          break;
        case 7:
          displayGrid[r][c] = '7';
          break;
        case 8:
          displayGrid[r][c] = '8';
          break;
        default:
          displayGrid[r][c] = '?';
      }

      checkSelectedPoint(r, c);
    }
  }
}

int MineSweeper::bombsAroundPoint(const int row, const int col)
{
  int result = 0;
  for(int r = row -1; r < row + 1; r++)
  {
    if(r < 0 || r >= numRows)
      continue;
    for(int c = col -1; c < col + 1; c++)
    {
      if(c < 0 || c >= numCols)
        continue;

      if(grid[r][c] == 1)
        result++;
    }
  }

  return result;
}

ostream& operator << (ostream& out, const MineSweeper& ms)
{
  out << ms.numRows << " " << ms.numCols << endl;
  for(int r = 0; r < ms.numRows; r++)
  {
    for(int c = 0; c < ms.numCols; c++)
      out << ms.grid[r][c] << ' ';
    out << endl;
  }

  return out;
}

istream& operator >> (istream& in, MineSweeper& ms)
{
  in >> ms.numRows;
  in >> ms.numCols;

  ms.resizeGrid();

  ms.numMines = 0;
  for(int r = 0; r < ms.numRows; r++)
    for(int c = 0; c < ms.numCols; c++)
    {
      in >> ms.grid[r][c];
      if(ms.grid[r][c] == 1)
        ms.numMines++;
    }
  return in;
}

void MineSweeper::resizeGrid()
{
  assert(numRows > 0);
  assert(numCols > 0);
  assert(numMines >= 0);

  grid.clear();
  displayGrid.clear();

  for(int r = 0; r < numRows; r++)
  {
    vector<int> tmpVector;
    grid.push_back(tmpVector);

    vector<char> tmpCharVector;
    displayGrid.push_back(tmpCharVector);

    for(int c = 0; c < numCols; c++)
    {
      grid[r].push_back(0);
      displayGrid[r].push_back(UNKNOWN);
    }
  }
}

int main(int argc, char* argv[])
{
  MineSweeper ms(5, 6, 7);
  cout << "MineSweeperGrid " << endl
       << ms << endl;

  while(!ms.getBombSelected())
  {
    cout << "DisplayGrid: " << endl;
    ms.displayToUser();

    cout << "Enter a grid a point to select: ";
    int row, col;
    cin >> row;
    cin >> col;

    ms.select(row, col);
  }

}

0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Article by: SunnyDark
This article's goal is to present you with an easy to use XML wrapper for C++ and also present some interesting techniques that you might use with MS C++. The reason I built this class is to ease the pain of using XML files with C++, since there is…
  Included as part of the C++ Standard Template Library (STL) is a collection of generic containers. Each of these containers serves a different purpose and has different pros and cons. It is often difficult to decide which container to use and …
The viewer will learn how to use and create new code templates in NetBeans IDE 8.0 for Windows.
The viewer will learn how to user default arguments when defining functions. This method of defining functions will be contrasted with the non-default-argument of defining functions.

704 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question