CF85D.Sum of Medians

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

In one well-known algorithm of finding the kk -th order statistics we should divide all elements into groups of five consecutive elements and find the median of each five. A median is called the middle element of a sorted array (it's the third largest element for a group of five). To increase the algorithm's performance speed on a modern video card, you should be able to find a sum of medians in each five of the array.

A sum of medians of a sorted kk -element set S=a1,a2,...,akS={a_{1},a_{2},...,a_{k}} , where a_{1}<a_{2}<a_{3}<...<a_{k} , will be understood by as

The operator stands for taking the remainder, that is stands for the remainder of dividing xx by yy .

To organize exercise testing quickly calculating the sum of medians for a changing set was needed.

输入格式

The first line contains number nn ( 1<=n<=1051<=n<=10^{5} ), the number of operations performed.

Then each of nn lines contains the description of one of the three operations:

  • add xx — add the element xx to the set;
  • del xx — delete the element xx from the set;
  • sum — find the sum of medians of the set.

For any add xx operation it is true that the element xx is not included in the set directly before the operation.

For any del xx operation it is true that the element xx is included in the set directly before the operation.

All the numbers in the input are positive integers, not exceeding 10910^{9} .

输出格式

For each operation sum print on the single line the sum of medians of the current set. If the set is empty, print 0.

Please, do not use the %lld specificator to read or write 64-bit integers in C++. It is preferred to use the cin, cout streams (also you may use the %I64d specificator).

输入输出样例

  • 输入#1

    6
    add 4
    add 5
    add 1
    add 2
    add 3
    sum
    

    输出#1

    3
    
  • 输入#2

    14
    add 1
    add 7
    add 2
    add 5
    sum
    add 6
    add 8
    add 9
    add 3
    add 4
    add 10
    sum
    del 1
    sum
    

    输出#2

    5
    11
    13
    
首页