Most Frequent Word Problem Statement

You are given two strings 'A' and 'B' composed of words separated by spaces. Your task is to determine the most frequent and lexicographically smallest word in string 'A' that is not present in string 'B'. If no such word exists in 'A', return -1.

Example:

Input:

'A' = "coding ninjas coding ninjas", 'B' = "data structures and algorithms"

Output:

coding

Explanation:

The words 'coding' and 'ninjas' are both absent from string 'B' and occur twice in 'A'. However, 'coding' is lexicographically smaller than 'ninjas', so the result is "coding".

Constraints:

• 1 <= T <= 10
• 1 <= |A|, |B| <= 10⁵ (Where |A|, |B| denote the length of strings 'A' and 'B' respectively)
• Time limit: 1 second

Note:

You don’t need to print anything. Implement the function and return the results as specified.

Input:

The first line contains an integer 'T' denoting the number of test cases. Each test case includes: 
- First line: A string 'A' consisting of lowercase English letters only.
- Second line: A string 'B' consisting of lowercase English letters only.

Output:

For each test case, return the most frequent and lexicographically smallest word in string 'A' that is not present in string 'B'. If no such word exists, return -1.