Codeforces Round 789 (Div. 1)
A
Tokitsukaze and Strange Inequality
Codeforces
1600
原题
←B →
翻译中…

Tokitsukaze has a permutation $p$ of length $n$. Recall that a permutation $p$ of length $n$ is a sequence $p_1, p_2, \ldots, p_n$ consisting of $n$ distinct integers, each of which from $1$ to $n$ ($1 \leq p_i \leq n$).

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She wants to know how many different indices tuples $[a,b,c,d]$ ($1 \leq a \lt b \lt c \lt d \leq n$) in this permutation satisfy the following two inequalities:

翻译中…

$p_a \lt p_c$ and $p_b \gt p_d$.

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Note that two tuples $[a_1,b_1,c_1,d_1]$ and $[a_2,b_2,c_2,d_2]$ are considered to be different if $a_1 \ne a_2$ or $b_1 \ne b_2$ or $c_1 \ne c_2$ or $d_1 \ne d_2$.

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Input

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The first line contains one integer $t$ ($1 \leq t \leq 1000$) — the number of test cases. Each test case consists of two lines.

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The first line contains a single integer $n$ ($4 \leq n \leq 5000$) — the length of permutation $p$.

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The second line contains $n$ integers $p_1, p_2, \ldots, p_n$ ($1 \leq p_i \leq n$) — the permutation $p$.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $5000$.

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Output

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For each test case, print a single integer — the number of different $[a,b,c,d]$ tuples.

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Note

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In the first test case, there are $3$ different $[a,b,c,d]$ tuples.

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$p_1 = 5$, $p_2 = 3$, $p_3 = 6$, $p_4 = 1$, where $p_1 \lt p_3$ and $p_2 \gt p_4$ satisfies the inequality, so one of $[a,b,c,d]$ tuples is $[1,2,3,4]$.

翻译中…

Similarly, other two tuples are $[1,2,3,6]$, $[2,3,5,6]$.

翻译中…

样例

Input #1
3
6
5 3 6 1 4 2
4
1 2 3 4
10
5 1 6 2 8 3 4 10 9 7
Output #1
3
0
28
InputCopy OutputCopy
题目信息
题号
1677A
时间限制
1.5 s
内存限制
256 MB
标签
暴力
数据结构
动态规划

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。