Non-Substring Subsequence

1000ms

262144K

Description:

Hr0d1y has $$$q$$$ queries on a binary string $$$s$$$ of length $$$n$$$. A binary string is a string containing only characters '0' and '1'.

A query is described by a pair of integers $$$l_i$$$, $$$r_i$$$ $$$(1 \leq l_i \lt r_i \leq n)$$$.

For each query, he has to determine whether there exists a good subsequence in $$$s$$$ that is equal to the substring $$$s[l_i\ldots r_i]$$$.

A substring $$$s[i\ldots j]$$$ of a string $$$s$$$ is the string formed by characters $$$s_i s_{i+1} \ldots s_j$$$.
String $$$a$$$ is said to be a subsequence of string $$$b$$$ if $$$a$$$ can be obtained from $$$b$$$ by deleting some characters without changing the order of the remaining characters.
A subsequence is said to be good if it is not contiguous and has length $$$\ge 2$$$. For example, if $$$s$$$ is "1100110", then the subsequences $$$s_1s_2s_4$$$ ("1100110") and $$$s_1s_5s_7$$$ ("1100110") are good, while $$$s_1s_2s_3$$$ ("1100110") is not good.

Can you help Hr0d1y answer each query?

Input:

The first line of the input contains a single integer $$$t$$$ ($$$1\leq t \leq 100$$$) — the number of test cases. The description of each test case is as follows.

The first line contains two integers $$$n$$$ ($$$2 \leq n \leq 100$$$) and $$$q$$$ ($$$1\leq q \leq 100$$$) — the length of the string and the number of queries.

The second line contains the string $$$s$$$.

The $$$i$$$-th of the next $$$q$$$ lines contains two integers $$$l_i$$$ and $$$r_i$$$ ($$$1 \leq l_i \lt r_i \leq n$$$).

Output:

For each test case, output $$$q$$$ lines. The $$$i$$$-th line of the output of each test case should contain "YES" if there exists a good subsequence equal to the substring $$$s[l_i...r_i]$$$, and "NO" otherwise.

You may print each letter in any case (upper or lower).

Sample Input:

Sample Output:

YES
NO
YES
NO
YES

Note:

In the first test case,

$$$s[2\ldots 4] = $$$ "010". In this case $$$s_1s_3s_5$$$ ("001000") and $$$s_2s_3s_6$$$ ("001000") are good suitable subsequences, while $$$s_2s_3s_4$$$ ("001000") is not good.
$$$s[1\ldots 3] = $$$ "001". No suitable good subsequence exists.
$$$s[3\ldots 5] = $$$ "100". Here $$$s_3s_5s_6$$$ ("001000") is a suitable good subsequence.

Informação

Provedor Codeforces

Código CF1451B