A15905. Range Sorting (Easy Version)
编程题
普及/提高-
知识点
题目描述
The only difference between this problem and the hard version is the constraints on $t$ and $n$ .
You are given an array $a$ , consisting of $n$ distinct integers $a_1, a_2, \ldots, a_n$ .
Define the beauty of an array $p_1, p_2, \ldots p_k$ as the minimum amount of time needed to sort this array using an arbitrary number of range-sort operations. In each range-sort operation, you will do the following:
- Choose two integers $l$ and $r$ ( $1 \le l < r \le k$ ).
- Sort the subarray $p_l, p_{l + 1}, \ldots, p_r$ in $r - l$ seconds.
Please calculate the sum of beauty over all subarrays of array $a$ .
A subarray of an array is defined as a sequence of consecutive elements of the array.
You are given an array $a$ , consisting of $n$ distinct integers $a_1, a_2, \ldots, a_n$ .
Define the beauty of an array $p_1, p_2, \ldots p_k$ as the minimum amount of time needed to sort this array using an arbitrary number of range-sort operations. In each range-sort operation, you will do the following:
- Choose two integers $l$ and $r$ ( $1 \le l < r \le k$ ).
- Sort the subarray $p_l, p_{l + 1}, \ldots, p_r$ in $r - l$ seconds.
Please calculate the sum of beauty over all subarrays of array $a$ .
A subarray of an array is defined as a sequence of consecutive elements of the array.
输入格式
Each test contains multiple test cases. The first line contains the number of test cases $t$ ( $1 \le t \le 5 \cdot 10^3$ ). The description of the test cases follows.
The first line of each test case contains a single integer $n$ ( $1 \le n \le 5 \cdot 10^3$ ) — the length of the array $a$ .
The second line of each test case consists of $n$ integers $a_1,a_2,\ldots, a_n$ ( $1\le a_i\le 10^9$ ). It is guaranteed that all elements of $a$ are pairwise distinct.
It is guaranteed that the sum of $n$ over all test cases does not exceed $5 \cdot 10^3$ .
The first line of each test case contains a single integer $n$ ( $1 \le n \le 5 \cdot 10^3$ ) — the length of the array $a$ .
The second line of each test case consists of $n$ integers $a_1,a_2,\ldots, a_n$ ( $1\le a_i\le 10^9$ ). It is guaranteed that all elements of $a$ are pairwise distinct.
It is guaranteed that the sum of $n$ over all test cases does not exceed $5 \cdot 10^3$ .
输出格式
For each test case, output the sum of beauty over all subarrays of array $a$ .
输入输出样例
输入 #1
5 2 6 4 3 3 10 6 4 4 8 7 2 5 9 8 2 4 6 12 2 6 13 3 15 5 10 8 16 9 11 18
输出 #1
1 2 8 16 232
说明/提示
In the first test case:
- The subarray $[6]$ is already sorted, so its beauty is $0$ .
- The subarray $[4]$ is already sorted, so its beauty is $0$ .
- You can sort the subarray $[6, 4]$ in one operation by choosing $l = 1$ and $r = 2$ . Its beauty is equal to $1$ .
The sum of beauty over all subarrays of the given array is equal to $0 + 0 + 1 = 1$ .In the second test case:
- The subarray $[3]$ is already sorted, so its beauty is $0$ .
- The subarray $[10]$ is already sorted, so its beauty is $0$ .
- The subarray $[6]$ is already sorted, so its beauty is $0$ .
- The subarray $[3, 10]$ is already sorted, so its beauty is $0$ .
- You can sort the subarray $[10, 6]$ in one operation by choosing $l = 1$ and $r = 2$ . Its beauty is equal to $2 - 1 = 1$ .
- You can sort the subarray $[3, 10, 6]$ in one operation by choosing $l = 2$ and $r = 3$ . Its beauty is equal to $3 - 2 = 1$ .
The sum of beauty over all subarrays of the given array is equal to $0 + 0 + 0 + 0 + 1 + 1 = 2$ .
- The subarray $[6]$ is already sorted, so its beauty is $0$ .
- The subarray $[4]$ is already sorted, so its beauty is $0$ .
- You can sort the subarray $[6, 4]$ in one operation by choosing $l = 1$ and $r = 2$ . Its beauty is equal to $1$ .
The sum of beauty over all subarrays of the given array is equal to $0 + 0 + 1 = 1$ .In the second test case:
- The subarray $[3]$ is already sorted, so its beauty is $0$ .
- The subarray $[10]$ is already sorted, so its beauty is $0$ .
- The subarray $[6]$ is already sorted, so its beauty is $0$ .
- The subarray $[3, 10]$ is already sorted, so its beauty is $0$ .
- You can sort the subarray $[10, 6]$ in one operation by choosing $l = 1$ and $r = 2$ . Its beauty is equal to $2 - 1 = 1$ .
- You can sort the subarray $[3, 10, 6]$ in one operation by choosing $l = 2$ and $r = 3$ . Its beauty is equal to $3 - 2 = 1$ .
The sum of beauty over all subarrays of the given array is equal to $0 + 0 + 0 + 0 + 1 + 1 = 2$ .