VK Cup 2022 - Отборочный раунд (Engine)
B
Going to the Cinema
Codeforces
1000
原题
← AC →
翻译中…

A company of $n$ people is planning a visit to the cinema. Every person can either go to the cinema or not. That depends on how many other people will go. Specifically, every person $i$ said: "I want to go to the cinema if and only if at least $a_i$ other people will go, not counting myself". That means that person $i$ will become sad if:

翻译中…
  • they go to the cinema, and strictly less than $a_i$ other people go; or
  • they don't go to the cinema, and at least $a_i$ other people go.
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In how many ways can a set of people going to the cinema be chosen so that nobody becomes sad?

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

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Each test case consists of two lines. The first line contains a single integer $n$ ($2 \le n \le 2 \cdot 10^5$) — the number of people in the company.

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The second line contains $n$ integers $a_1, a_2, \ldots, a_n$ ($0 \le a_i \le n - 1$) — integers from peoples' claims.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

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Output

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For each test case, print a single integer — the number of different ways to choose a set of people going to the cinema so that nobody becomes sad.

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Note

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In the first test case, both people want to go to the cinema if and only if the other person goes. There are two valid options: either both people go, or neither of them goes. However, if just one of them goes, both will be sad.

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In the second test case, everyone has to go to the cinema. In any other case, someone will be sad.

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In the third test case, there are three valid options: person number $2$ goes to the cinema; or persons with indices $2, 3, 4, 7$ go; or all eight people go.

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样例

Input #1
4
2
1 1
7
0 1 2 3 4 5 6
8
6 0 3 3 6 7 2 7
5
3 0 0 3 3
Output #1
2
1
3
2
InputCopy OutputCopy
题目信息
题号
1781B
时间限制
2 s
内存限制
512 MB
标签
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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。