Java Subarray HackerRank Solution

Problem:-

We define the following:

• A subarray of an -element array is an array composed from a contiguous block of the original array's elements. For example, if , then the subarrays are , , , , , and . Something like  would notbe a subarray as it's not a contiguous subsection of the original array.
• The sum of an array is the total sum of its elements.
  • An array's sum is negative if the total sum of its elements is negative.
  • An array's sum is positive if the total sum of its elements is positive.

Given an array of  integers, find and print its number of negative subarrays on a new line.

Input Format

The first line contains a single integer, , denoting the length of array . 
The second line contains  space-separated integers describing each respective element, , in array .

Constraints

Output Format

Print the number of subarrays of  having negative sums.

Sample Input

5
1 -2 4 -5 1

Sample Output

9

Explanation

There are nine negative subarrays of :

Thus, we print  on a new line.

Solution:-

import java.io.*;

import java.util.*;

import java.text.*;

import java.math.*;

import java.util.regex.*;

public class Solution {

public static void main(String[] args) {

Scanner sc = new Scanner(System.in);

int length = sc.nextInt();

int[] arr = new int[length];

int first = sc.nextInt();

arr[0] = first;

int count = first < 0 ? 1 : 0;

for (int i = 1; i < length; i++){

int num = sc.nextInt();

arr[i] = arr[i - 1] + num;

if (arr[i] < 0){

count++;

}

for (int j = 0; j < i; j++){

int sub_result = arr[i] - arr[j];

if (sub_result < 0){

count++;

}

}

}

System.out.print(count);

}

}