Codeforces Global Round 23
A
Maxmina
Codeforces
800
原题
←B →
翻译中…

You have an array $a$ of size $n$ consisting only of zeroes and ones and an integer $k$. In one operation you can do one of the following:

翻译中…
  • Select $2$ consecutive elements of $a$ and replace them with their minimum (that is, let $a := [a_{1}, a_{2}, \ldots, a_{i-1}, \min(a_{i}, a_{i+1}), a_{i+2}, \ldots, a_{n}]$ for some $1 \le i \le n-1$). This operation decreases the size of $a$ by $1$.
  • Select $k$ consecutive elements of $a$ and replace them with their maximum (that is, let $a := [a_{1}, a_{2}, \ldots, a_{i-1}, \max(a_{i}, a_{i+1}, \ldots, a_{i+k-1}), a_{i+k}, \ldots, a_{n}]$ for some $1 \le i \le n-k+1$). This operation decreases the size of $a$ by $k-1$.
翻译中…

Determine if it's possible to turn $a$ into $[1]$ after several (possibly zero) operations.

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 1000$). The description of the test cases follows.

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The first line of each test case contains two integers $n$ and $k$ ($2 \le k \le n \le 50$), the size of array $a$ and the length of segments that you can perform second type operation on.

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The second line contains $n$ integers $a_{1}, a_{2}, \ldots, a_{n}$ ($a_i$ is $0$ or $1$), elements of array $a$.

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Output

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For each test case, if it is possible to turn $a$ into $[1]$, print "YES", otherwise print "NO".

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Note

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In the first test case, you can perform the second type operation on second and third elements so $a$ becomes $[0, 1]$, then you can perform the second type operation on first and second elements, so $a$ turns to $[1]$.

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In the fourth test case, it's obvious to see that you can't make any $1$, no matter what you do.

翻译中…

In the fifth test case, you can first perform a type 2 operation on the first three elements so that $a$ becomes $[1, 0, 0, 1]$, then perform a type 2 operation on the elements in positions two through four, so that $a$ becomes $[1, 1]$, and finally perform the first type operation on the remaining elements, so that $a$ becomes $[1]$.

翻译中…

样例

Input #1
7
3 2
0 1 0
5 3
1 0 1 1 0
2 2
1 1
4 4
0 0 0 0
6 3
0 0 1 0 0 1
7 5
1 1 1 1 1 1 1
5 3
0 0 1 0 0
Output #1
YES
YES
YES
NO
YES
YES
YES
InputCopy OutputCopy
题目信息
题号
1746A
时间限制
1 s
内存限制
256 MB
标签
构造
贪心

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