CF431E.Chemistry Experiment

普及/提高-

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题目描述

One day two students, Grisha and Diana, found themselves in the university chemistry lab. In the lab the students found nn test tubes with mercury numbered from 11 to nn and decided to conduct an experiment.

The experiment consists of qq steps. On each step, one of the following actions occurs:

  1. Diana pours all the contents from tube number pip_{i} and then pours there exactly xix_{i} liters of mercury.
  2. Let's consider all the ways to add viv_{i} liters of water into the tubes; for each way let's count the volume of liquid (water and mercury) in the tube with water with maximum amount of liquid; finally let's find the minimum among counted maximums. That is the number the students want to count. At that, the students don't actually pour the mercury. They perform calculations without changing the contents of the tubes.

Unfortunately, the calculations proved to be too complex and the students asked you to help them. Help them conduct the described experiment.

输入格式

The first line contains two integers nn and qq ( 1<=n,q<=1051<=n,q<=10^{5} ) — the number of tubes ans the number of experiment steps. The next line contains nn space-separated integers: h1,h2,...,hnh_{1},h_{2},...,h_{n} ( 0<=hi<=1090<=h_{i}<=10^{9} ), where hih_{i} is the volume of mercury in the іі -th tube at the beginning of the experiment.

The next qq lines contain the game actions in the following format:

  • A line of form " 11 pip_{i} xix_{i} " means an action of the first type ( 1<=pi<=n; 0<=xi<=1091<=p_{i}<=n; 0<=x_{i}<=10^{9} ).
  • A line of form " 22 viv_{i} " means an action of the second type ( 1<=vi<=10151<=v_{i}<=10^{15} ).

It is guaranteed that there is at least one action of the second type. It is guaranteed that all numbers that describe the experiment are integers.

输出格式

For each action of the second type print the calculated value. The answer will be considered correct if its relative or absolute error doesn't exceed 10410^{-4} .

输入输出样例

  • 输入#1

    3 3
    1 2 0
    2 2
    1 2 1
    2 3
    

    输出#1

    1.50000
    1.66667
    
  • 输入#2

    4 5
    1 3 0 1
    2 3
    2 1
    1 3 2
    2 3
    2 4
    

    输出#2

    1.66667
    1.00000
    2.33333
    2.66667
    
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