Equal Arrays

Moderate

0/80

Average time to solve is 20m

Contributed by

10 upvotes

Asked in company

Problem statement

You are given two arrays 'A' and 'B' of length 'N' and 'M' respectively. You can perform the following operation any number of times on 'A' and 'B'.

1. Replace any subarray of the array with the sum of the elements in the subarray. For example :- If we have an array 'A' = [2, 3, 5, 6, 1], then we can replace the subarray from index 1 to index 3 (0-based indexing) i.e. [3, 5, 6] with its sum i.e. 3 + 5 + 6 = 14 to get 'A' =  [2, 14, 1].

You want to make 'A' and 'B' equal. Return the maximum possible length of arrays 'A' and 'B' such that 'A' is equal to 'B'. If it is impossible to make 'A' and 'B' equal then return -1.

A subarray is a contiguous part of the array.

For Example:-

Let 'N' = 4, 'M' = 5, 'A' = [2, 1, 4, 3], 'B' = [2, 5, 1, 1, 1].
 We can perform operations on 'A' from index 2 to 3 and on 'B' from index 3 to 5 (1-based indexing).
'A' and 'B' after performing the operation is [2, 5, 3].
The maximum possible length is 3.

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

Input Format:-

First-line contains an integer 'T', which denotes the number of test cases.
For every test case:-
First-line contains two integers 'N' and 'M', denoting the length of the array 'A' and 'B'.
Second-line contains 'N' space-separated integers, elements of array 'A'.
Third-line contains 'M' space-separated integers, elements of array 'B'.

Output Format:-

For each test case, Return the maximum possible length of arrays 'A' and 'B' such that 'A' is equal to 'B'. If it is impossible to make 'A' and 'B' equal then return -1.

Note:-

You don’t need to print anything. Just implement the given function.

Constraints:-

1 <= 'T' <= 10
1 <= 'N','M' <= 10^5
1 <= 'A[i]', 'B[i]' <= 10^5

The Sum of 'N' overall test cases does not exceed 10^5.
Time Limit: 1 sec

Sample Input 1:-

Sample Output 1:-

-1
3

Explanation of sample input 1:-

First test case:-
It can be proven that we cannot make 'A' and 'B' equal.
So our answer is -1.

Second test case:-
We can perform operations on 'A' from index 1 to 2 and from index 4 to 5 (1-based indexing).
'A' and 'B' after performing the operation is [4, 2, 5].
The maximum possible length is 3.

Sample Input 2:-

Sample Output 2:-

 -1
 1

Console