/* 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
		int[]arr ={1,2,1,1,2,1,3};
		int k= 2;
		System.out.println(countAllSubArrays(arr,k));
	}
	static int countAllSubArrays(int [] arr,int k){
		int[]preSum = new int[arr.length];
		preSum[0] = arr[0];
		for(int i=1;i<arr.length;i++){
			preSum[i] = preSum[i-1]+arr[i];
		}
		int cnt = 0;
		HashMap<Integer,Integer>map = new HashMap<>();
		for(int i=0;i<arr.length;i++){
			if(map.containsKey(preSum[i]-k)){
				cnt+=map.get(preSum[i]-k);
			}
			map.put(preSum[i],map.getOrDefault(preSum[i],0)+1);
		}
		return cnt;
	}
}

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