memory game

//
//  main.cpp
//  Exercise 12.16
//
//  Created by Gustavo Silveira on 11/21/13.
//  Copyright (c) 2013 Gustavo Silveira. All rights reserved.
//
// !! The "system("clear")" doesn't work on my compiler, but maybe it will work on yours.

#include <iostream>
#include <time.h>
#include <stdlib.h>
#include <cstdlib>
#include <unistd.h>
#include <term.h>

using namespace std;

int C(4);
int r1, c1, r2, c2; //row one and two, collum one and two
int a,b,c,d;

int tries = 0; //accumulator for how many tries untill the end


char front[4][4] = {
  {'1','2','3','4'},
  {'5','6','7','8'},
  {'1','2','3','4'},
  {'5','6','7','8'},
};
char back [4][4] = {
  {'*','*','*','*'},
  {'*','*','*','*'},
  {'*','*','*','*'},
  {'*','*','*','*'},
};

void swap(char&a, char&b);
void sort(char Front[][4]);
void print(char ar[][4]);
bool check(char Back[][4]);
void input();


int main ()
{
  srand(time(0));
  system("clear");
  sort(front); //Shuffle numbers in the chosen array
  print(back); //Print the game

  while(true) {

    input(); //Inputs and checks if it is a valid number

    if (front[r1][c1] == front[r2][c2]) { //If the two cards match it will print those cards
      back[r1][c1] = front[r1][c1];
      back[r2][c2] = front[r2][c2];
      tries++;


      system("clear"); //Clear screen (doesn't work on XCode)

      check(back);
      print(back);

    }
    if (front[r1][c1] != front[r2][c2]) { //If cards don't match it will print and after some seconds it be back "*"

      back[r1][c1] = front[r1][c1];
      back[r2][c2] = front[r2][c2];

      system("clear");

      print(back);

      cout << endl;

      sleep(3); //Wait to come to the previous screen

      system("clear");

      back[r1][c1] = '*';
      back[r2][c2] = '*';

      print(back);

    }
    tries++; //count how many tries untill find all the matches

    if (check(back) == true) { //Check if the game is over and tells how many tries were needed
      cout << "You finished in " << tries << " tries.";
      cout << endl;
      break;
    }
  }

  return 0;
}

void input() {

  cout << endl << "Type 4 ints separated by a space, row 1, column 1, row 2, column 2: ";
  cin >> a >> b >> c >> d;
  cout << endl;


  r1=a-1;
  c1=b-1;
  r2=c-1;
  c2=d-1;



  while (((r1==r2) && (c1==c2)) || ((r1>=C)||(c1>=C)||(r2>=C)||(c2>=C))) {
    cout << "Wrong value, try different cards: ";
    cin >> a >> b >> c >> d;
    cout << endl;

    r1=a-1;
    c1=b-1;
    r2=c-1;
    c2=d-1;

  }
}

bool check(char Back[][4]) {
  for (int r=0; r<C; r++) {
    for (int c=0; c<C; c++) {
      if (back[r][c] == '*') {
    return false;
      }
    }
  }

  return true;
}

void print(char ar[][4]) {
  cout << "############## Memory Game ##############\n";
  cout << "   1  2  3  4\n";
  cout << "   ----------\n";
  for (int r=0; r<C; r++) {
    cout << r+1 << "| ";
    for (int c=0; c<C; c++) {
      cout << ar[r][c] << "  ";
    }
    cout << endl;
  }
}

void swap(char&a, char&b) {
  char tmp = a;
  a = b;
  b = tmp;
}

void sort(char Front[][4]) {
  for (int i=0; i<500; i++) {
    swap(front[rand()%4][rand()%4], front[rand()%4][rand()%4]);
  }
}