Yandex.Algorithm 2011: Round 1
D
Sum of Medians
Codeforces
2300
原题
← CE →
翻译中…

In one well-known algorithm of finding the $*k*$-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.

翻译中…

A sum of medians of a sorted $*k*$-element set $*S* = {*a*_{1}, *a*_{2}, ..., *a*_{*k*}}$, where $*a*_{1} < *a*_{2} < *a*_{3} < ... < *a*_{*k*}$, will be understood by as

翻译中…

image

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The image operator stands for taking the remainder, that is image stands for the remainder of dividing $*x*$ by $*y*$.

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

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Input

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The first line contains number $*n*$ ($1 ≤ *n* ≤ 10^{5}$), the number of operations performed.

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Then each of $*n*$ lines contains the description of one of the three operations:

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  • add x — add the element $*x*$ to the set;
  • del x — delete the element $*x*$ from the set;
  • sum — find the sum of medians of the set.
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For any add x operation it is true that the element $*x*$ is not included in the set directly before the operation.

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

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All the numbers in the input are positive integers, not exceeding $10^{9}$.

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Output

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

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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).

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样例

Input #1
6
add 4
add 5
add 1
add 2
add 3
sum
Output #1
3
InputCopy OutputCopy
Input #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
Output #2
5
11
13
InputCopy OutputCopy
题目信息
题号
85D
时间限制
3 s
内存限制
256 MB
标签
二分
暴力
数据结构
模拟

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。