P18491 [CodeChef] EVSTR
普及
题目描述

An even sequence has the following property: each maximal contiguous subsequence which contains only equal integers (i.e. the same integer repeated a number of times) has an even length. In particular, the empty sequence is even. A subsequence is maximal if it is not contained in a larger contiguous subsequence which contains only equal integers.
Chef was given an integer sequence $A_1, A_2, \ldots, A_N$ by his friend Mr. Z. He may perform the following operation any number of times: either delete an element of the current sequence (if it is non-empty) or insert an integer anywhere in the current sequence (possibly at the beginning or at the end).
Find the minimum number of operations needed to make the sequence even.

-----Input-----
- The first line of the input contains a single integer $T$ denoting the number of test cases. The description of $T$ test cases follows.
- The first line of each test case contains a single integer $N$.
- The second line contains $N$ space-separated integers $A_1, A_2, \ldots, A_N$.

-----Output-----
For each test case, print a single line containing one integer — the minimum number of operations.

-----Constraints-----
- $1 \leq T \leq 10$
- $1 \leq N \leq 2 \cdot 10^5$
- $1 \leq A_i \leq N$ for each valid $i$
- the sum of $N$ over all test cases does not exceed $2 \cdot 10^6$

-----Subtasks-----
Subtask #1 (10 points): $N \leq 18$
Subtask #2 (10 points): $A_i \leq A_{i+1}$ for each valid $i$
Subtask #3 (20 points): $N \leq 3,000$
Subtask #4 (20 points): $A_i \leq 26$ for each valid $i$
Subtask #5 (40 points): original constraints

-----Example Input-----
2
4
1 1 2 1
11
2 2 2 10 2 10 1 1 5 3 5

-----Example Output-----
2
3

-----Explanation-----
Example case 1: Here are two ways to make the sequence even using $2$ operations:
- Delete the first element $1$ and the only element $2$, resulting in a sequence $(1, 1)$, which is even.
- Delete the last element $1$ and insert $2$ at the end, resulting in a sequence $(1,1,2,2)$, which is even.
It can be proved that one operation is not enough to make the initial sequence even.

输入格式

见题面

输出格式

见题面

样例输入
['2', '4', '1 1 2 1', '11', '2 2 2 10 2 10 1 1 5 3 5']
样例输出
['2', '3']