关于教室那题，答完题后才想出个思路，有AC的大佬看看可以帮我看看写的有没有问题否。。 def cmp(x, y): if x[0] > y[0]: return 1 elif x[0] == y[0]: if x[1] > y[1]: return 1 else: return -1 else: return -1 if __name__ == '__main__': n = input() data_list = [] while n > 0: m = raw_input().strip().split(' ') m = map(int, m) data_list.append(m) n -= 1 data_list.sort(cmp=cmp) res = [] for i in range(0, len(data_list)-1): if data_list[i][1] > data_list[i+1][0]: res.append(data_list[i]) if len(res) == 0: for i in data_list: print i elif len(res) == 1: print res[0] elif len(res) == 2: if res[0][0] == res[1][0]: for i in res: print i else: print 0 else: print 0