第一次做出广搜好吗！

black_n_red.py

#coding: utf-8
# http://acm.hdu.edu.cn/showproblem.php?pid=1312

while True:
    queue = []

    #input W and H
    WnH = raw_input()
    width = int(WnH.split(' ')[0])
    height = int(WnH.split(' ')[1])

    if width == 0 and height == 0:
        break

    # input matrix
    matrix = [[] for i in range(width)]
    for l_idx in range(height):
        line_in = raw_input()
        for c_idx in range(len(line_in)):
            column = matrix[c_idx]
            char = line_in[c_idx]
            column.append(char)
            if char == '@':
                queue.append((c_idx, l_idx))

    count = 0
    # search
    while True:
        # print queue
        new_queue = []
        for item in queue:
            x = item[0]
            y = item[1]
            # visited
            if matrix[x][y] == '.':
                count = count + 1
            # if matrix[x][y] == '#':
            #     continue
            matrix[x][y] = '#'
            #x-1
            if(x-1 >= 0) and (matrix[x-1][y] != '#'):
                new_queue.append((x-1, y))
                matrix[x-1][y] = '#'
            #x+1
            if(x+1 < width) and (matrix[x+1][y] != '#'):
                new_queue.append((x+1, y))
                matrix[x+1][y] = '#'
            #y-1
            if(y-1 >= 0) and (matrix[x][y-1] != '#'):
                new_queue.append((x, y-1))
                matrix[x][y-1] = '#'
            #y+1
            if(y+1 < height) and (matrix[x][y+1] != '#'):
                new_queue.append((x, y+1))
                matrix[x][y+1] = '#'
        if len(new_queue) <= 0:
            break
        queue = new_queue

    print count + 1 # 好像答案包括起点