/******************************************************************************
 *                                                                            *
 *    4 On a line - a old school game with lot of fun                         *
 *                                                                            *
 * Author:  Casper Thede Olsen & Anne Christine Tang                          *
 * Date:    20-03-2007                                                        *
 * Version  0.2                                                               *
 *                                                                            *
 * Purpose: A project in school where we had free hands to write a program.   *
 *                                                                            *
 *                                                                            *
 * Usage:                                                                     *
 *                                                                            *
 * License: Open Source - please give some credits if you use some of it.     *
 *                                                                            *
 *****************************************************************************/

#include <stdio.h>
#include <stdlib.h>

char matrix[6][7]; /* board size is [6][7] */

void init_matrix(void);
void disp_matrix(void);
void get_x_move(void);
void get_o_move(void);
char check(void);

int main(){
    
    char done;
    /*sets Done to ' ' and interlize the matrix so everything in matrix to ' '*/
    init_matrix();
    done = ' ';
    do {
      disp_matrix();
      get_x_move();
      done = check();
      if(done != ' ') break;
      disp_matrix();
      get_o_move();
      done = check();
    } while(done == ' ');
    printf("done is %c\n", done);
    disp_matrix();
    system("PAUSE");
}


/* Sub rutines section under here */

/* Initialize the matrix. */
void init_matrix(void)
{
  int i;
  int j;

  for(i=0; i<6;i++)
    for(j=0; j<7; j++) matrix[i][j] =  ' ';
}

/* Display the matrix on the screen. */
void disp_matrix(void)
{
  int t;
  printf("  1   2   3   4   5   6   7\n|---|---|---|---|---|---|---|\n");  
  for(t=0; t<6; t++) {
    printf("| %c | %c | %c | %c | %c | %c | %c |",matrix[t][0],
            matrix[t][1], matrix [t][2], matrix [t][3],
            matrix[t][4], matrix [t][5], matrix [t][6]);
    if(t!=6)printf("\n|---|---|---|---|---|---|---|\n");
  }
  printf("\n");
}

/* get X move*/
void get_x_move(void)
{
  /*makes 2 temporarily variables*/
  int y;
  int x; 
  
  printf("X turn\n");
  printf("Enter your move:\n ");
  scanf("%d", &x);
  x--;
  y = 0;
  printf("debug ID X = %d Y = %d\n", x, y ); /*!DEBUG!*/
  if (matrix[y][x] != ' '){
    printf("Invalid move, try again.\n");
    get_x_move();
  }
  for(y=5; y>=0; y--) {
    if(matrix[y][x] == ' '){
       matrix[y][x] = 'x';
       break;
      }
  }
}

/* get O move*/
void get_o_move(void)
{
  /*makes 2 temporarily variables*/
  int y;
  int x; 
  
  printf("O turn\n");
  printf("Enter your move:\n ");
  scanf("%d", &x);
  x--;
  y = 0;
  printf("debug ID X = %d Y = %d\n", x, y ); /*!DEBUG!*/
  if (matrix[y][x] != ' '){
    printf("Invalid move, try again.\n");
    get_o_move();
  }
  for(y=5; y>=0; y--) {
    if(matrix[y][x] == ' '){
       matrix[y][x] = 'O';
       break;
      }
  }
}
/* Check for winners */
char check(void)
{
     int i;
     int j;
     
     for(i=0; i<6; i++) {
        for(j=0; j<4; j++) {
          if(matrix[i][j] != ' ' &&
             matrix[i][j] == matrix[i][j+1] &&
             matrix[i][j] == matrix[i][j+2] &&
             matrix[i][j] == matrix[i][j+3]) return matrix[i][j];
          }
     }
     
     for(i=0; i<7; i++) {
        for(j=0; j<3; j++) {
          if(matrix[j][i] != ' ' &&
            matrix[j][i] == matrix[j+1][i] &&
            matrix[j][i] == matrix[j+2][i] &&
            matrix[j][i] == matrix[j+3][i]) return matrix[j][i];
        }
     }
     
     for(i=0; i<4; i++) {
        for(j=0; j<3; j++) { 
          if(matrix[j][i] != ' ' &&
            matrix[j][i] == matrix[j+1][i+1] &&
            matrix[j][i] == matrix[j+2][i+2] &&
            matrix[j][i] == matrix[j+3][i+3]) return matrix[j][i];
        }
     }
     /*PROBLEM START*/
     for(i=3; i<7; i++) {
        for(j=0; j<3; j++) {
          if(matrix[j][i] != ' ' &&
            matrix[j][i] == matrix[j-1][i-1] &&
            matrix[j][i] == matrix[j-2][i-2] &&
            matrix[j][i] == matrix[j-3][i-3]) return matrix[j][i];
        }
     }
     /*PROBLEM END*/
     return ' ';
}