Codeforces Round 1095 (Div. 2)
C
Mental Monumental (Easy Version)
Codeforces
1500
原题
← BD →
翻译中…

This is the easy version of this problem. The difference between the versions is that in this version, you are required to find only the value of $f(a)$.

翻译中…

For any array $[c_1, c_2, \ldots, c_m]$, we define $f(c)$ as the maximum possible $\operatorname{mex}(c)$$^{\text{∗}}$ that can be achieved by performing the following operation exactly once:

翻译中…
  • Choose an integer array $[b_1, b_2, \ldots, b_m]$ such that $b_i \ge 1$ for all $1 \le i \le m$;
  • Set $c_i := c_i \, \bmod \, b_i$$^{\text{†}}$ for every $1 \le i \le m$.
翻译中…

You are given an array $a$ consisting of $n$ non-negative integers. Determine the value of $f(a)$.

翻译中…

$^{\text{∗}}$$\operatorname{mex}(c)$ denotes the minimum excluded (MEX) of the integers in $c$. For example, $\operatorname{mex}([2,2,1])=0$ because $0$ does not belong to the array, and $\operatorname{mex}([0,3,1,2])=4$ because $0$, $1$, $2$, and $3$ appear in the array, but $4$ does not.$^{\text{†}}$$u \bmod v$ denotes the remainder from dividing $u$ by $v$.

翻译中…

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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The first line of each testcase contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the length of the array $a$.

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The second line of each testcase contains $n$ integers $a_1, a_2, \ldots, a_n$ ($0 \le a_i \le 10^6$) — the elements of the array $a$.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$. It is guaranteed that the sum of $\max(a_1,a_2,\ldots,a_n)$ over all test cases does not exceed $10^6$.

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Output

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For each testcase, output a single integer — the value of $f(a)$.

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Note

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For the first testcase, choosing $b = [1, 2, 3, 4]$ leaves $a$ unchanged and we have $\operatorname{mex}(a) = 4$.

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For the second testcase, choosing $b = [3, 3]$ makes $a = [0, 1]$. Thus, we have $\operatorname{mex}(a) = 2$.

翻译中…

样例

Input #1
4
4
0 1 2 3
2
6 7
6
8 1 7 6 4 3
9
9 9 8 2 4 4 3 5 3
Output #1
4
2
5
6
InputCopy OutputCopy
题目信息
题号
2226C
时间限制
4 s
内存限制
256 MB
标签
二分
数据结构
贪心
数学
双指针

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