codeforces 151（完全）

最近變懶了，好久沒寫題解了。。

這場codeforces 是在實驗室做的，當晚實驗室竟然有8個人同時做codeforces，創下了我們學校集訓隊熬夜做codeforces的記錄，12級的一兩個同學上升勢頭很猛，贊一個。

說一下題目吧：

A：水題

B ：水題

C ： 比水題稍難

D：　閱讀理解題吧，讀懂了就秒掉了

Ｅ題：

寫了一個比較挫的英文

problem E: we can also use BIT to solve this problem. first we should
read all the

 queries and change every query (v,k) into (depth , left , right) :depth
is the depth of

 the k sons of v,left and right are the indexes of vector W[d](it saves
all the nodes with

 depth of d),then we can answer all the queries in the same depth together
. So we

 transform the problem to another simple problem ,how many distinct
values in an

 interval .it's easy to solve it just use BIT (off line
). 

My Code　：http://codeforces.com/contest/246/submission/2632645