1 人解决，5 人已尝试。
1 份提交通过，共有 7 份提交。
9.9 EMB 奖励。
单点时限: 2.0 sec
内存限制: 256 MB
You are given a sequence $a_1, a_2, \dots, a_n$. The task is to perform the following queries on it:
Type 1. Given two integers $l$ and $r$ . Reorder the elements of the sequence in such a way (changed part of the sequence is in brackets):
$$a_1, a_2, \dots, a_n \Rightarrow a_1, a_2, \dots, a_{l-2}, a_{l-1}, [a_{l+1}, a_l, a_{l+3}, a_{l+2}, \dots, a_r, a_{r-1}], a_{r+1}, a_{r+2}, \dots , a_n$$
That is swap the first two elements of segment $[l,r]$, the second two elements, and so on.
Type 2. Given two integers $l$ and $r$, print the value of sum $\sum_{ i = l }^{ r } a_i$.
The first line contains two integers $n$ and $q$. The second line contains $n$ integers $a_1, a_2, \dots, a_n$, denoting initial sequence.
Each of the next $q$ lines contains three integers $tp_i, l_i, r_i$, where $tp_i$ denotes the type of the query, and $l_i$ are $r_i$ parameters of the query. It’s guaranteed that for a first-type query $r-l+1$ will be even.
For each query of the second type print the required sum.
6 4 1 2 3 4 5 6 1 2 5 2 2 3 2 3 4 2 4 5
5 7 9
1 人解决，5 人已尝试。
1 份提交通过，共有 7 份提交。
9.9 EMB 奖励。