逻辑分析题，注意以下关键性质：

一个球被染成什么颜色取决于最后一次的染色情况，如果没有被染过色，那么默认是白色

结果总是的2的乘方

1 class LittleElephantAndIntervalsDiv1: 2     def getNumber(self, m, l, r): 3         # the last color 4         a = [-1] * m 5         for rou in range(0, len(l)): 6             for i in range(l[rou]-1, r[rou]): 7                 a[i] = rou 8                  9         # count key round10         s = set(a)11         12         # calc13         tot = 2 ** (len(s) - (1 if -1 in s else 0))14         return tot15     16     17     18 # test 19 o = LittleElephantAndIntervalsDiv1()20 21 # test case22 assert(o.getNumber(4, (1,2,3), (1,2,3)) == 8)23 assert(o.getNumber(3, (1,1,2), (3,1,3)) == 4)24 print('ok')