题目描述
The Company Dynamic Rankings has developed a new kind of computer that is no longer satisfied with the query like to simply find the k-th smallest number of the given N numbers. They have developed a more powerful system such that for N numbers a[1], a[2], ..., a[N], you can ask it like: what is the k-th smallest number of a[i], a[i+1], ..., a[j]? (For some i<=j, 0<k<=j+1-i that you have given to it). More powerful, you can even change the value of some a[i], and continue to query, all the same.
Your task is to write a program for this computer, which - Reads N numbers from the input (1 <= N <= 50,000) - Processes M instructions of the input (1 <= M <= 10,000). These instructions include querying the k-th smallest number of a[i], a[i+1], ..., a[j] and change some a[i] to t.给出一个长度为n的序列a，两种操作
C x v：将第x个元素的值改成v
Q l r k：查询区间[l,r]中第k大的元素
输入
The first line of the input is a single number X (0 < X <= 4), the number of the test cases of the input. Then X blocks each represent a single test case.
The first line of each block contains two integers N and M, representing N numbers and M instruction. It is followed by N lines. The (i+1)-th line represents the number a[i]. Then M lines that is in the following format Q i j k or C i t It represents to query the k-th number of a[i], a[i+1], ..., a[j] and change some a[i] to t, respectively. It is guaranteed that at any time of the operation. Any number a[i] is a non-negative integer that is less than 1,000,000,000. There're NO breakline between two continuous test cases.第一行为一个整数t表示用例组数，每组用例第一行为两个整数n和m分别表示序列长度和操作数，第二行n个整数表示序列a，之后m行每行一种操作
（0< t<=4，1<=n<=50000，1<=m<=10000）输出
For each querying operation, output one integer to represent the result. (i.e. the k-th smallest number of a[i], a[i+1],..., a[j])
There're NO breakline between two continuous test cases.对于每次查询，输出查询结果