Codeforces Round 905 (Div. 3)
B
Chemistry
Codeforces
900
原题
← AC →
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You are given a string $s$ of length $n$, consisting of lowercase Latin letters, and an integer $k$.

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You need to check if it is possible to remove exactly $k$ characters from the string $s$ in such a way that the remaining characters can be rearranged to form a palindrome. Note that you can reorder the remaining characters in any way.

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A palindrome is a string that reads the same forwards and backwards. For example, the strings "z", "aaa", "aba", "abccba" are palindromes, while the strings "codeforces", "reality", "ab" are not.

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Input

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Each test consists of multiple test cases. The first line contains a single integer $t$ ($1 \leq t \leq 10^4$) — the number of the test cases. This is followed by their description.

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The first line of each test case contains two integers $n$ and $k$ ($0 \leq k \lt n \leq 10^5$) — the length of the string $s$ and the number of characters to be deleted.

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The second line of each test case contains a string $s$ of length $n$, consisting of lowercase Latin letters.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

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Output

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For each test case, output "YES" if it is possible to remove exactly $k$ characters from the string $s$ in such a way that the remaining characters can be rearranged to form a palindrome, and "NO" otherwise.

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You can output the answer in any case (uppercase or lowercase). For example, the strings "yEs", "yes", "Yes", and "YES" will be recognized as positive answers.

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Note

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In the first test case, nothing can be removed, and the string "a" is a palindrome.

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In the second test case, nothing can be removed, but the strings "ab" and "ba" are not palindromes.

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In the third test case, any character can be removed, and the resulting string will be a palindrome.

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In the fourth test case, one occurrence of the character "a" can be removed, resulting in the string "bb", which is a palindrome.

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In the sixth test case, one occurrence of the characters "b" and "d" can be removed, resulting in the string "acac", which can be rearranged to the string "acca".

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In the ninth test case, one occurrence of the characters "t" and "k" can be removed, resulting in the string "aagaa", which is a palindrome.

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样例

Input #1
14
1 0
a
2 0
ab
2 1
ba
3 1
abb
3 2
abc
6 2
bacacd
6 2
fagbza
6 2
zwaafa
7 2
taagaak
14 3
ttrraakkttoorr
5 3
debdb
5 4
ecadc
5 3
debca
5 3
abaac
Output #1
YES
NO
YES
YES
YES
YES
NO
NO
YES
YES
YES
YES
NO
YES
InputCopy OutputCopy
题目信息
题号
1883B
时间限制
2 s
内存限制
256 MB
标签
字符串

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。