2017微软秋季校园招聘在线编程笔试-#1402 : MS Recognition

http://hihocoder.com/problemset/problem/1402

题意理解：M和S都很大，并且相互离的很远，M和S的两个端点不一样，M不平衡，所以端点的中点到重心的距离和端点的距离比值》0.5就是M。很奇怪为什么画一条支线看个数会不行，或者是参数设置的不好？

急转弯：端点和重心，距离关系

算法：bfs找端点

数据结构：无

from __future__ import print_function##'dfs and math'__author__ = 'hjkruclion'import sysimport mathdef read_int():    return list(map(int, sys.stdin.readline().split()))def read_str():    return sys.stdin.readline().split()[0]maxn = 500 + 100dx = [-1, -1, -1, 0, 1, 1, 1, 0]dy = [-1, 0, 1, 1, 1, 0, -1, -1]def dcmp(x):    if math.fabs(x) < 1e-4:        return 0    if x > 0:        return 1    return -1a = [['.' for j in range(maxn)] for i in range(maxn)]vis = [[0 for j in range(maxn)] for i in range(maxn)]G = []N, M = read_int()for i in range(N):    a[i] = read_str()    # for j in range(M):    #     a[i][j] = t[j]    # if i <= 5:    #     print(len(a[i]))# print(a[7][7] == '#')resM = 0resS = 0def calcu(x, y, x1, y1, x2, y2):    if x1 == x2:        if dcmp((x1 - x)) == 0:            return 1        elif dcmp((x1 - x)) > 0:            return 1        else:            return -1    else:        t = (y2 - y1) / (x2 - x1) * (x - x1) + y1 - y        if dcmp(t) > 0:            return 1        elif dcmp(t) == 0:            return 1        else:            return -1def dist(x1, y1, x2, y2):    return math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2))def bfs(xs, ys, tag):    global G, vis    q = [(xs, ys)]    vis[xs][ys] = tag    ansx = xs    ansy = ys    if tag == 1:        G.append((xs, ys))    while(len(q) != 0):        x, y = q.pop(0)        for k in range(8):            nx = x + dx[k]            ny = y + dy[k]            if nx >= 0 and nx < N and ny >= 0 and ny < M and vis[nx][ny] != tag and a[nx][ny] == '#':                q.append((nx, ny))                vis[nx][ny] = tag                if tag == 1:                    G.append((nx, ny))                ansx = nx                ansy = ny    return ansx, ansyfor i in range(N):    for j in range(M):        if vis[i][j] != 0 or a[i][j] == '.':            continue        # print('hh')        G = []        x1, y1 = bfs(i, j, 1)        x2, y2 = bfs(x1, y1, 2)        num = len(G)        ans = 0        zx = 0        zy = 0        for _ in range(num):            # ans += calcu(G[_][0], G[_][1], x1, y1, x2, y2)            zx += G[_][0]            zy += G[_][1]        zx /= num        zy /= num        dist1 = dist(zx, zy, (x1 + x2) / 2, (y1 + y2) / 2)        dist2 = dist(x1, y1, x2, y2)        if dist1 / (dist2 / 2) >= 0.5:            resM += 1        else:            resS += 1        # if math.fabs(ans) >= num / 2:        #     resM += 1        # else:        #     resS += 1print(resM, resS)