Question

Reposting question with additional information.

I am writing a java program that has the computer play a game of ConnectFour with the user, I am having trouble with the code that tells who wins the game. when I play the game after getting four in a row the program just continues to go on. I believe my FindLocalWinner method should be correct, so I need help with the findWinner method.

/**
* Check for a win starting at a given location and heading in a
* given direction.
*
* Returns the char of the player with four in a row starting at
* row r, column c and advancing rowOffset, colOffset each step.
* Returns NONE if no player has four in a row here, or if there
* aren't four spaces starting here.
*
* For example, if rowOffset is 1 and colOffset is 0, we would
* advance the row index by 1 each step, checking for a vertical
* win. Similarly, if rowOffset is 0 and colOffset is 1, we would
* check for a horizonal win.
* @param board The game board.
* @param r Row index of where win check starts
* @param c Column index of where win check starts
* @param rowOffset How much to move row index at each step
* @param colOffset How much to move column index at each step
* @return char of winner from given location in given direction
* or NONE if no winner there.
*/
public static char findLocalWinner(char[][] board, int r, int c,
int rowOffset, int colOffset) {
// TODO You have to write this.
char player = board[r][c];
if(player == NONE) {
   //player = NONE;
   return NONE;
}
for (int i = 0; i < 4; i++ ) {
int col = c+i*colOffset;
int row = r+i*rowOffset;
if(player != NONE || c > COLUMNS || c < 0 || r > ROWS || r < 0) {
  
return NONE;
}if (board[row][col] != player) {
return NONE;
}

  
  
}

   return player;
}
/**
* Checks entire board for a win (4 in a row).
*
* @param board The game board.
* @return char (HUMAN or COMPUTER) of the winner, or NONE if no
* winner yet.
*/
public static char findWinner(char[][] board) {
// TODO You have to write this.
// HINT: You should call the findLocalWinner method to help you
//douyble for look watch out for rowoffset
//for(int i = 0; i < COLUMNS; i ++) {

//}
char Winner = NONE;
for(int row = 0; row < ROWS; row++) {
for(int col = 0; col < COLUMNS; col++) {
if(Winner == NONE) { //makes sure winner is NONE unless it finds human or comp
Winner = findLocalWinner(board,row,col,0,1);
}if(Winner == NONE) {
Winner = findLocalWinner(board,row,col,1,0);
}if(Winner == NONE) {
Winner = findLocalWinner(board,row,col,1,1);
}if(Winner == NONE) {
Winner = findLocalWinner(board,row,col,-1,1);
}
}
}
return Winner;
}

Answer 1

public static char findWinner(char[][] board) {
        
        // check for a row.
        for(int row = 0; row < ROWS; row++) {
                for(int col = 0; col < COLUMNS - 3; col++) {
                        char w = findLocalWinner(board, row, col, 0, 1);
                        if(w != NONE) {
                                return w;
                        }
                }
        }
        
        // check for a column.
        for(int row = 0; row < ROWS - 3; row++) {
                for(int col = 0; col < COLUMNS; col++) {
                        char w = findLocalWinner(board, row, col, 1, 0);
                        if(w != NONE) {
                                return w;
                        }
                }
        }
        
        // check for a major diagonal. (top left to bottom right)
        for(int row = 0; row < ROWS - 3; row++) {
                for(int col = 0; col < COLUMNS - 3; col++) {
                        char w = findLocalWinner(board, row, col, 1, 1);
                        if(w != NONE) {
                                return w;
                        }
                }
        }
        
        // check for a minor diagonal. (bottom left to top right)
        for(int row = ROWS - 1; row >= 3; row++) {
                for(int col = 0; col < COLUMNS - 3; col++) {
                        char w = findLocalWinner(board, row, col, -1, 1);
                        if(w != NONE) {
                                return w;
                        }
                }
        }
        
        return NONE;
}