Codeforces Round 807 (Div. 2)
E
Mark and Professor Koro
Codeforces
2300
原题
← DF →
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After watching a certain anime before going to sleep, Mark dreams of standing in an old classroom with a blackboard that has a sequence of $n$ positive integers $a_1, a_2,\dots,a_n$ on it.

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Then, professor Koro comes in. He can perform the following operation:

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  • select an integer $x$ that appears at least $2$ times on the board,
  • erase those $2$ appearances, and
  • write $x+1$ on the board.
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Professor Koro then asks Mark the question, "what is the maximum possible number that could appear on the board after some operations?"

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Mark quickly solves this question, but he is still slower than professor Koro. Thus, professor Koro decides to give Mark additional challenges. He will update the initial sequence of integers $q$ times. Each time, he will choose positive integers $k$ and $l$, then change $a_k$ to $l$. After each update, he will ask Mark the same question again.

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Help Mark answer these questions faster than Professor Koro!

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Note that the updates are persistent. Changes made to the sequence $a$ will apply when processing future updates.

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Input

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The first line of the input contains two integers $n$ and $q$ ($2\leq n\leq 2\cdot 10^5$, $1\leq q\leq 2\cdot 10^5$) — the length of the sequence $a$ and the number of updates, respectively.

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The second line contains $n$ integers $a_1,a_2,\dots,a_n$ ($1\leq a_i\leq 2\cdot 10^5$)

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Then, $q$ lines follow, each consisting of two integers $k$ and $l$ ($1\leq k\leq n$, $1\leq l\leq 2\cdot 10^5$), telling to update $a_k$ to $l$.

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Output

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Print $q$ lines. The $i$-th line should consist of a single integer — the answer after the $i$-th update.

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Note

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In the first example test, the program must proceed through $4$ updates.

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The sequence after the first update is $[2,3,2,4,5]$. One sequence of operations that achieves the number $6$ the following.

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  • Initially, the blackboard has numbers $[2,3,2,4,5]$.
  • Erase two copies of $2$ and write $3$, yielding $[3,4,5,\color{red}{3}]$.
  • Erase two copies of $3$ and write $4$, yielding $[4,5,\color{red}{4}]$.
  • Erase two copies of $4$ and write $5$, yielding $[5,\color{red}{5}]$.
  • Erase two copies of $5$ and write $6$, yielding $[\color{red}{6}]$.
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Then, in the second update, the array is changed to $[2,3,2,4,3]$. This time, Mark cannot achieve $6$. However, one sequence that Mark can use to achieve $5$ is shown below.

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  • Initially, the blackboard has $[2,3,2,4,3]$.
  • Erase two copies of $2$ and write $3$, yielding $[3,4,3,\color{red}{3}]$.
  • Erase two copies of $3$ and write $4$, yielding $[3,4,\color{red}{4}]$.
  • Erase two copies of $4$ and write $5$, yielding $[3,\color{red}{5}]$.
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In the third update, the array is changed to $[2,3,2,1,3]$. One way to achieve $4$ is shown below.

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  • Initially, the blackboard has $[2,3,2,1,3]$.
  • Erase two copies of $3$ and write $4$, yielding $[2,2,1,\color{red}{4}]$.
翻译中…

样例

Input #1
5 4
2 2 2 4 5
2 3
5 3
4 1
1 4
Output #1
6
5
4
5
InputCopy OutputCopy
Input #2
2 1
200000 1
2 200000
Output #2
200001
InputCopy OutputCopy
题目信息
题号
1705E
时间限制
2 s
内存限制
256 MB
标签
二分
位运算
暴力
组合数学
数据结构
贪心

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