#include <stdio.h>
#define BOARDSIZE 10

int check_board(char[][]);
void check_winner(int);
int check_badmove(char[][], int xmove, int ymove);
char switch_curr_player(char);

main() {

  /* declare all main variables */
  char board[BOARDSIZE][BOARDSIZE];
  int i,j, done, rc, movedone;
  int nummoves;
  int xmove, ymove;
  char curr_player;
  
  /* initialize board to the character '_' */
  for(i=0; i<BOARDSIZE; i++) {
    for (j=0; j<BOARDSIZE; j++) {
      board[i][j] = '_';
    }
  }  

  /* call the draw_board function to draw the playing board */
  draw_board(board);

  /* initialize loop variables */
  nummoves = 0;
  done = 0;
  curr_player = 'X';

  /* outer loop, goes until sombody wins or there is a draw */
  while(!done) {

    /* inner loop: ask cuur player to make a move, if invalid move is made, ask again */
    movedone = 0;
    while(!movedone) {
      xmove = ymove = -1;
      printf("player %c: enter a move in x,y coordinates (x,y): ", curr_player);
      scanf("%d,%d", &xmove, &ymove);

      /* check if inputted move is valid */
      if (check_badmove(board, xmove, ymove)) {
	printf("Illegal move, try again\n");
      } else {
	/* fill in the board with curr_player's symbol */
	board[xmove][ymove] = curr_player;
	nummoves++;

	movedone++;
      }

      draw_board(board);
    }
    
     
    /* check to see if the last move found a winner! */
    rc = check_board(board);
    if (rc) {
      check_winner(rc);
      done++;
    }

    if (nummoves == BOARDSIZE * BOARDSIZE) {
      printf("Draw!\n");
      done++;
    }
    /* switch to whomever makes the next move */
    curr_player = switch_curr_player(curr_player);
  }

}

char switch_curr_player(char curr) {
  if (curr == 'X') {
    return('O');
  }
  return('X');
}

int check_badmove(char inboard[BOARDSIZE][BOARDSIZE], int xmove, int ymove) {
  int rc;
  rc = 0;

  if (inboard[xmove][ymove] != '_') {
    rc = 1;
  } else if (xmove > (BOARDSIZE-1) || xmove < 0) {
    rc = 1;
  } else if (ymove > (BOARDSIZE-1) || ymove < 0) {
    rc = 1;
  }

  return(rc);
}

void check_winner(int winner) {
    switch(winner) {
    case 1:
      printf("X wins!\n");
      break;
    case 2: 
      printf("O wins!\n");
      break;
    default:
      printf("no winner yet\n");
      break;
    }
}  

int check_board(char inboard[BOARDSIZE][BOARDSIZE]) {
  int i, j, diagidx;
  int rc;
  int xdiaga, xdiagb, odiaga, odiagb;
  int xrow, orow, xcol, ocol;

  xdiaga = xdiagb = odiaga = odiagb = 1;

  diagidx = 0;
  rc = 0;

  for (i=0; i<BOARDSIZE; i++) {

    xrow = orow = 1;
    for (j=0; j<BOARDSIZE; j++) {
      if (inboard[i][j] == 'X') {
	orow = 0;
      } else if (inboard[i][j] == 'O') {
	xrow = 0;
      } else {
	orow = xrow = 0;
      }
    }

    xcol = ocol = 1;
    for (j=0; j<BOARDSIZE; j++) {
      if (inboard[j][i] == 'X') {
	ocol = 0;
      } else if (inboard[j][i] == 'O') {
	xcol = 0;
      } else {
	ocol = xcol = 0;
      }
    }

    if (ocol || orow) {
      printf("O: %d %d\n", ocol, orow);
      rc = 2;
    } else if (xcol || xrow) {
      printf("X: %d %d\n", xcol, xrow);
      rc = 1;
    }

    if (rc) {
      break;
    }

    
    if(inboard[i][diagidx] == 'X') {
      odiaga = 0;
    } else if (inboard[i][diagidx] == 'O') {
      xdiaga = 0;
    } else {
      xdiaga = odiaga = 0;
    }

    if(inboard[(BOARDSIZE-1)-i][diagidx] == 'X') {
      odiagb = 0;
    } else if (inboard[(BOARDSIZE-1)-i][diagidx] == 'O') {
      xdiagb = 0;
    } else {
      xdiagb = odiagb = 0;
    }

    diagidx++;
  }

  if (!rc) {
    if (xdiaga || xdiagb) {
      rc = 1;
    } else if (odiaga || odiagb) {
      rc = 2;
    }    
  }

  return(rc);
}

int draw_board(char inboard[BOARDSIZE][BOARDSIZE]) {
  int i, j;
  
  for(i=0; i<BOARDSIZE; i++) {
    for (j=0; j<BOARDSIZE; j++) {
      printf("| %c ", inboard[i][j]);
    }
    printf("|\n");
  }

  return (0);
}