/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
	}
}
 
 
class Solution {
    public int cntSubarrays(int[] arr, int k) {
         // HashMap to store prefix sums frequencies
        Map<Integer, Integer> prefixSums = new HashMap<>();
        int res = 0;
        int currSum = 0;
 
        for (int i = 0; i < arr.length; i++) {
            // Add current element to sum so far.
            currSum += arr[i];
 
            // If currSum is equal to desired sum
            // then a new subarray is found.
            if (currSum == k)
                res++;
 
            // Check if the difference exists in the prefixSums map.
            if (prefixSums.containsKey(currSum - k))
                res += prefixSums.get(currSum - k);
 
            // Add currSum to the set of prefix sums.
            prefixSums.put(currSum, prefixSums.getOrDefault(currSum, 0) + 1);
        }
 
        return res;
    }  
}

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