Subarray Sum Equals K

Given an array A of integers of size N and an integer K, find the number of contiguous subarrays (subsegments) whose sum is exactly equal to K. The array can contain negative numbers, positive numbers, or zeros. An efficient solution with a time complexity of \(O(N)\) is expected due to potentially large input sizes.

Details:

• The input consists of two lines. The first line contains two integers N and K.
• The second line contains N space-separated integers representing the array A.
• Output a single integer representing the number of subarrays whose sum is exactly equal to K.

Example:

Input:
5 5
1 2 3 4 5
Output:
2

</p>

inputFormat

The first line of input contains two space-separated integers \(N\) and \(K\), where \(N\) is the number of elements in the array and \(K\) is the target sum.

The second line contains \(N\) space-separated integers representing the elements of the array \(A\).

outputFormat

Output a single integer which is the number of contiguous subarrays whose sum is exactly \(K\).

## sample

5 5
1 2 3 4 5

2