src/surrounded-regions/res.js

/**
 * res.js
 * @authors Joe Jiang (hijiangtao@gmail.com)
 * @date    2017-03-10 22:17:27
 * @version $Id$
 *
 * @param {character[][]} board
 * @return {void} Do not return anything, modify board in-place instead.
 */

let solve = function(board) {
    if (board.length === 0) {
        return ;
    }
    
    let rowlen = board.length,
        collen = board[0].length,
        rowecp = rowlen-1,
        colecp = collen-1;

    if (rowlen <= 2 || collen <= 2) {
    	return ;
    }
        
    for (let i=0; i<collen; i++) {
        // 判断第一行是否存在'O'
        if (board[0][i] === 'O') {
        	board[0][i] = '1';
        	if (board[1][i] === 'O' && i!==0 && i!==collen-1) {
        		judZero(1, i, rowlen, collen, board);
        	}
        }
        // judZero(0, i, rowlen, collen, board);
        
        // 判断最后一行是否存在'O'
        if (board[rowecp][i] === 'O') {
        	board[rowecp][i] = '1';
        	if (board[rowecp-1][i] === 'O' && i!==0 && i!==collen-1) {
        		judZero(rowecp-1, i, rowlen, collen, board);
        	}
        }

        // judZero(rowecp, i, rowlen, collen, board);
    }
    
    
    for (let i=1; i<rowecp; i++) {
        // 判断第一列是否存在'O'
        if (board[i][0] === 'O') {
        	board[i][0] = '1';
        	if (board[i][1] === 'O' && i!==0 && i!==rowecp) {
        		judZero(i, 1, rowlen, collen, board);
        	}
        }

        // judZero(i, 0, rowlen, collen, board);
        
        // 判断最后一列是否存在'O'
        if (board[i][colecp] === 'O') {
        	board[i][colecp] = '1';
        	if (board[i][colecp-1] === 'O' && i!==0 && i!==rowecp) {
        		judZero(i, colecp-1, rowlen, collen, board);
        	}
        }

        // judZero(i, colecp, rowlen, collen, board);
    }
    
    for (let i=0; i<rowlen; i++) {
        for (let j=0; j<collen; j++) {
            if (board[i][j] === '1') {
                board[i][j] = 'O';
            } else if (board[i][j] === 'O') {
                board[i][j] = 'X';
            }
        }
    }
    
    return ;
};

let judZero = function(x, y, rowlen, collen, matrix) {
    // if (matrix[x][y] !== 'O') {
    //     return ;
    // }
    
    matrix[x][y] = '1';
    
    if (x-1 > 1 && matrix[x-1][y] === 'O') {
        judZero(x-1, y, rowlen, collen, matrix);
    }
    if (x+1 < rowlen-2 && matrix[x+1][y] === 'O') {
        judZero(x+1, y, rowlen, collen, matrix);
    }
    if (y-1 > 1 && matrix[x][y-1] === 'O') {
        judZero(x, y-1, rowlen, collen, matrix);
    }
    if (y+1 < collen-2 && matrix[x][y+1] === 'O') {
        judZero(x, y+1, rowlen, collen, matrix);
    }
};