a_185_Largest_Subarray_Sum_0.java

import java.util.* ;

public class a_185_Largest_Subarray_Sum_0 {
    public static void main(String[] args) {
        // int arr[] = {15, -2, 2, -8, 1 , 7, 10 } ;
        int arr[] = {-1, 1, -1, 1 } ;

        HashMap<Integer, Integer> map = new HashMap<>() ;
        // (sum ,idx)

        int sum = 0 ; 
        int len = 0 ;
        for(int j=0; j<arr.length; j++){
            sum += arr[j] ;
            if(map.containsKey(sum)){
                len = Math.max(len, j-map.get(sum) )  ;
            }
            else{
                map.put(sum, j )  ;
            }
        }

        System.out.println("Largest subarray with sum is 0 = " + len);
        
    }
}