2014北京網絡預選賽1008（線段樹區間操作）HDU5039

Hilarity

Time Limit: 12000/6000 MS (Java/Others) Memory Limit: 262144/262144 K (Java/Others)
Total Submission(s): 211 Accepted Submission(s): 51


Problem Description After June 1st, elementary students of Ted Land are still celebrating "The Sacred Day of Elementary Students”. They go to the streets and do some elementary students stuff. So we call them "elementary students". There are N cities in Ted Land. But for simplicity, the mayor Matt only built N - 1 roads so that all cities can reach each other. Some of the roads are occupied by the "elementary students". They will put an celebration hat on everyone who goes through the road without one. But if someone goes through the road with a celebration hat on his head, "elementary students" will steal the hat for no reason. Since Matt doesn’t have a celebration hat, he wants to know how many different paths in his land that he can end up with a hat. Two paths are considered to be different if and only if they have different start city or end city. As the counsellor of the mayor Matt, you have to answer this question for him. The celebration elementary students are not stable: sometimes a new crowd of elementary students go to an empty road; sometimes the elementary students on a road will go back home and remain the road empty. Matt will send you the monitor about the change of elementary students on road and ask you the question above. You will be fired if you answer wrong.
Input The first line of the input contains an integer T, denoting the number of testcases. Then T test cases follow.

For each test case, the first line contains N (1<=N<=30000) describing the number of cities.

Then N lines follow. The ith line of these contains the name of the ith city, it’s a string containing only letters and will not be longer than 10.

The following N - 1 lines indicate the N - 1 edges between cities. Each of these lines will contain two strings for the cities’ name and a integer for the initial status of the edge (0 for empty, 1 for crowded).

Then an integer M (1<=M<=60000) describes the number of queries. There are two kinds of query:

● "M i" means the status changing of the ith (starting from 1) road (0 to 1, 1 to 0);
● "Q" means that Matt asks you the number of different paths.
Output For each test case, first output one line “Case #x:”, where x is the case number (starting from 1).

Then for each “Q” in input, output a line with the answer.
Sample Input

1
5
a
b
c
d
e
a b 1
b c 0
c d 1
d e 1
7
Q
M 1
Q
M 3
Q
M 4
Q

Sample Output

Case #1:
12
8
8
0

題意：給出一棵n個點的樹，邊權為0或1，可以修改任何一條邊的值，查詢整棵樹上有多少對u,v之間路徑的異或值為1
思路：首先根據異或的性質不難發現求xor(u,v)=xor(1,u)^xor(1,v)
所以可以用線段樹維護每個xor（1,u）
1.修改操作，假如要修改u與其父親的邊，則以u為根的子樹的xor全都改變了，即取反
所以可以先將整棵樹的用DFS序列化，也就是所謂的樹形轉線性，每個節點及其子樹都是一段連續的線段
2.查詢，直接查詢整個線段就好了