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Problem

Submissions

Subsequence Game

Contributed by

Jaypal Mudaliyar

Last Updated: 23 Feb, 2023

Medium

0/80

Avg time to solve 20 mins

Success Rate 65 %

1 upvotes

Problem Statement

Shail is very fond of strings. So his parents on his birthday gave him a task on strings as a present. The task is as follows:

There is the main string ‘STR’ of length ‘N’ consisting of only lowercase English letters, and there is an array of strings ‘ARR’ of length ‘M’, where each string consists of only lowercase English letters. Now Shail has to find the count of such strings in the array ‘ARR’ which occurs as a subsequence in the string ‘STR’ and tell it to their parents.

But Shail is busy with his birthday celebration and cannot solve the task, but want to make his parents happy by giving them the answer to the task, So being his friend he asked you to solve this problem, Can you help him?.

NOTE: A subsequence of a given sequence, is a sequence that can be derived from the given sequence by deleting some or no elements without changing the order of the remaining elements. For more details please visit this link.

EXAMPLE :

Input: ‘N’ = 5, ‘M' = 2, ‘STR’ = “abcde” , ‘ARR’ = [“ad”, “cb”]

Output: 1
In this case, string “ad” occurs as a subsequence in the string ‘STR’ and the index of the match is ‘0’ and ‘3’ respectively. Also, string “cb” isn’t a subsequence because there is no occurrence of ‘b’ after the first ‘c’ at index ‘2’. Hence the output will be ‘1’.

Detailed explanation ( Input/output format, Notes, Images )

Input Format :

The first line will contain the integer ‘T’, the number of test cases.

The first line of each test case contains two integers, ‘N’ and ‘M’ , denoting the length of string and array respectively.

Followed by a line containing the string ‘STR’ of length.

Followed by ‘M’ lines, each containing the string of the array ‘ARR’.

Output format :

For each test case, print the count of strings in the array ‘ARR’ that occurs as a subsequence in the string ‘STR’.

Note :

You don't need to print anything. It has already been taken care of. Just implement the given function.

Constraints :

1 <= ‘T’ <= 10
1 <= ‘N’ <= 10^4
STR.length = N
1 <= ‘M’ <= 10^4
‘STR’ only consists of lowercase English letters.
It is guaranteed that sum of ‘N’ over all test cases is <= 10^5
It is guaranteed that sum of lengths of strings in array ‘ARR’ over all test cases is <= 10^5
Time Limit: 1 sec

Sample Input 1 :

2
5 1
virat
vat
10 3
helloworld
oo
abcdefghijk
hewd

Sample Output 1 :

1
2

Explanation Of Sample Input 1 :

For the first test case,
The matching sequence index for string “vat” is = [‘0’, ‘3’, ‘4’].

Hence, the output will be: 1

For the second test case,
The matching sequence index for string “oo” is = [‘4’, ‘6’].
There is no matching sequence index for string “abcdefghijk”.
The matching sequence index for string “hewd” is = [‘0’, ‘1’, ‘5’, ‘9’].

Hence, the output will be: 2

Sample Input 2 :

2
10 4
btovxbkumc
btovxbku
to
zueoxxxjme
yjkclbkbtl
26 2
bcdaefhgikjlmonprqstuvxwzy
empty
abcdefghijklmnopqrstuvwxyz

Sample Output 2 :

2
1

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