アルゴリズム-柱と梁

def solution(n, build_frame):
    answer = []
    bos=[]
    pils =[]
    def ck_bo(x,y, add=True):
        if (((x,y-1) in pils) or ((x+1,y-1) in pils)) or (((x-1, y) in bos) and ((x+1, y) in bos)):
            if add:
                bos.append((x,y))
            return True
        return False
    def ck_pil(x,y, add=True):
        if ((x, y-1) in pils) or ((x,y) in bos) or ((x-1, y) in bos) or y ==0:
            if add:
                pils.append((x,y))
            return True
        return False
    def del_bo(x,y):
        try:
            bos.remove((x,y))
            if (x-1,y) in bos:
                if not ck_bo(x-1, y, False):
                    bos.append((x,y))
                    return False
            if (x+1,y) in bos:
                if not ck_bo(x+1, y, False):
                    bos.append((x,y))
                    return False
            if (x,y) in pils:
                if not ck_pil(x,y, False):
                    bos.append((x,y))
                    return False
            if (x+1, y) in pils:
                if not ck_pil(x+1, y,False):
                    bos.append((x,y))
                    return False
            return True
        except:
            return False
    def del_pil(x,y):
        try:
            pils.remove((x,y))
            if (x,y+1) in bos:
                if not ck_bo(x, y+1, False):
                    pils.append((x,y))
                    return False
            if (x-1,y+1) in bos:
                if not ck_bo(x-1, y+1, False):
                    pils.append((x,y))
                    return False
            if (x,y+1) in pils:
                if not ck_pil(x,y+1, False):
                    pils.append((x,y))
                    return False
            return True
        except:
            return False

    for frame in build_frame:
        x, y  =  frame[0], frame[1]
        if frame[-1] == 1:
            if frame[-2] == 0:
                ck_pil(x,y)
            else:
                ck_bo(x,y)
        else:
            if frame[-2] == 0:
                del_pil(x,y)
            else:
                del_bo(x,y)
    bos = [list(bo)+[1] for bo in bos]
    pils = [list(pil)+[0] for pil in pils]
    answer = bos + pils
    answer.sort()
    return answer