A11397. Eyes Closed
编程题
普及/提高-
知识点
题目描述
Vasya and Petya were tired of studying so they decided to play a game. Before the game begins Vasya looks at array $a$ consisting of $n$ integers. As soon as he remembers all elements of $a$ the game begins. Vasya closes his eyes and Petya does $q$ actions of one of two types:
$1)$ Petya says 4 integers $l1,r1,l2,r2$ — boundaries of two non-intersecting segments. After that he swaps one random element from the $[l1,r1]$ segment with another random element from the $[l2,r2]$ segment.
$2)$ Petya asks Vasya the sum of the elements of $a$ in the $[l,r]$ segment.
Vasya is a mathematician so he answers Petya the mathematical expectation of the sum of the elements in the segment.
Your task is to write a program which will answer the second type questions as Vasya would do it. In other words your program should print the mathematical expectation of the sum of the elements of $a$ in the $[l,r]$ segment for every second type query.
$1)$ Petya says 4 integers $l1,r1,l2,r2$ — boundaries of two non-intersecting segments. After that he swaps one random element from the $[l1,r1]$ segment with another random element from the $[l2,r2]$ segment.
$2)$ Petya asks Vasya the sum of the elements of $a$ in the $[l,r]$ segment.
Vasya is a mathematician so he answers Petya the mathematical expectation of the sum of the elements in the segment.
Your task is to write a program which will answer the second type questions as Vasya would do it. In other words your program should print the mathematical expectation of the sum of the elements of $a$ in the $[l,r]$ segment for every second type query.
输入格式
The first line contains two integers $n,q$ ( $2<=n<=10^{5},1<=q<=10^{5}$ ) — the number of elements in the array and the number of queries you need to handle.
The second line contains $n$ integers $a_{i}$ ( $1<=a_{i}<=10^{9}$ ) — elements of the array.
The next $q$ lines contain Petya's actions of type 1 or 2.
If it is a type $1$ action then the line contains $5$ integers $1,l1,r1,l2,r2$ ( $1<=l1<=r1<=n,1<=l2<=r2<=n$ ).
If it is a type $2$ query then the line contains $3$ integers $2,l,r$ ( $1<=l<=r<=n$ ).
It is guaranteed that there is at least one type $2$ query and segments $[l1,r1],[l2,r2]$ don't have common elements.
The second line contains $n$ integers $a_{i}$ ( $1<=a_{i}<=10^{9}$ ) — elements of the array.
The next $q$ lines contain Petya's actions of type 1 or 2.
If it is a type $1$ action then the line contains $5$ integers $1,l1,r1,l2,r2$ ( $1<=l1<=r1<=n,1<=l2<=r2<=n$ ).
If it is a type $2$ query then the line contains $3$ integers $2,l,r$ ( $1<=l<=r<=n$ ).
It is guaranteed that there is at least one type $2$ query and segments $[l1,r1],[l2,r2]$ don't have common elements.
输出格式
For each type $2$ query print one real number — the mathematical expectation of the sum of elements in the segment.
Your answer will be considered correct if its absolute or relative error doesn't exceed $10^{-4}$ — formally, the answer is correct if  where $x$ is jury's answer and $y$ is yours.
Your answer will be considered correct if its absolute or relative error doesn't exceed $10^{-4}$ — formally, the answer is correct if  where $x$ is jury's answer and $y$ is yours.
输入输出样例
输入 #1
4 4 1 1 2 2 1 2 2 3 3 2 1 2 1 1 2 3 4 2 1 2
输出 #1
3.0000000 3.0000000
输入 #2
10 5 1 1 1 1 1 2 2 2 2 2 1 1 5 6 10 2 1 5 1 1 5 6 10 1 1 5 6 10 2 6 10
输出 #2
6.0000000 8.0400000
输入 #3
10 10 1 2 3 4 5 6 7 8 9 10 1 1 5 6 10 1 1 5 6 10 2 1 5 1 1 3 6 9 2 1 3 1 5 7 8 10 1 1 1 10 10 2 1 5 2 7 10 2 1 10
输出 #3
23.0000000 14.0000000 28.0133333 21.5733333 55.0000000