Superior Substring

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Algorithms, Binary Search, Easy, Hash Maps, Searching, Sorting, String Manipulation

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Problem

You are given a string $S$ of length $N$ . If a string contains at least one character whose frequency is greater than or equal to the half of the length of the string, then the string is called superior.

You are required to find the length of the longest superior substring available in the given string $S$ .

Note: Here half is considered under integer division i.e. $9 / 2 = 4$ , $3 / 2 = 1$ etc.

Input format

First line: Integer $T$ that represents the total number of test cases
For each test case:
- First line: Integer $N$ that represents the length of the string $S$
- Next line: String $S$ of the length $N$

Output format

For each test case, print the length of the longest superior substring in a new line.

Constraints

$1 \le T \le 10$
$1 \le N \le 10^5$
The string $S$ contains only lowercase English alphabets.

Sample Input

2
5
abcde
14
ababbbacbcbcca

Sample Output

3
13

Time Limit: 2

Memory Limit: 256

Source Limit:

Explanation

Sample test case $2$ : We can select the substring starting from index $1$ to $13$ , here the frequency of $b$ is $6$ which is greater than or equal to $13 / 2 = 6$ .
Note that, there can be multiple possible substrings.

Contributers:

Sanjay Gidwani

Ivan Safonov