CF1955D · Inaccurate Subsequence Search

• 难度：1400
• 标签：data structures、two pointers
• 链接：https://codeforces.com/problemset/problem/1955/D
• 时间限制：2 seconds　内存限制：256 megabytes
• 出现位置：假期自习包/B-单调栈与单调队列

中文题意

以下为官方英文题意（课堂讲解时请要求学生能用自己的话复述条件与目标）。

Maxim has an array $a$ of $n$ integers and an array $b$ of $m$ integers ($m \le n$). Maxim considers an array $c$ of length $m$ to be good if the elements of array $c$ can be rearranged in such a way that at least $k$ of them match the elements of array $b$. For example, if $b = [1, 2, 3, 4]$ and $k = 3$, then the arrays $[4, 1, 2, 3]$ and $[2, 3, 4, 5]$ are good (they can be reordered as follows: $[1, 2, 3, 4]$ and $[5, 2, 3, 4]$), while the arrays $[3, 4, 5, 6]$ and $[3, 4, 3, 4]$ are not good. Maxim wants to choose every subsegment of array $a$ of length $m$ as the elements of array $c$. Help Maxim count how many selected arrays will be good. In other words, find the number of positions $1 \le l \le n - m + 1$ such that the elements $a_l, a_{l+1}, \dots, a_{l + m - 1}$ form a good array.

Note（官方）： In the first example, all subsegments are good. In the second example, good subsegments start at positions $1$, $2$, and $3$. In the third example, good subsegments start at positions $1$ and $2$.

输入格式（中文）

The first line contains an integer $t$ ($1 \le t \le 10^4$) — the number of test cases. The first line of each test case contains three integers $n$, $m$, and $k$ ($1 \le k \le m \le n \le 2 \cdot 10^5$) — the number of elements in arrays $a$ and $b$, the required number of matching elements. The second line of each test case contains $n$ integers $a_1, a_2, \dots, a_n$ ($1 \le a_i \le 10^6$) — the elements of array $a$. Elements of the array $a$ are not necessarily unique. The third line of each test case contains $m$ integers $b_1, b_2, \dots, b_m$ ($1 \le b_i \le 10^6$) — the elements of array $b$. Elements of the array $b$ are not necessarily unique. It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$. Similarly, it is guaranteed that the sum of $m$ over all test cases does not exceed $2 \cdot 10^5$.

输出格式（中文）

For each test case, output the number of good subsegments of array $a$ on a separate line.

样例

样例 1

输入：

5
7 4 2
4 1 2 3 4 5 6
1 2 3 4
7 4 3
4 1 2 3 4 5 6
1 2 3 4
7 4 4
4 1 2 3 4 5 6
1 2 3 4
11 5 3
9 9 2 2 10 9 7 6 3 6 3
6 9 7 8 10
4 1 1
4 1 5 6
6

输出：

4
3
2
4
1