Diagonal Difference Solution in Java | HackerRank | Diagonal Difference HackerRank Solution

Diagonal Difference Solution in Java | HackerRank | Diagonal Difference HackerRank Solution

Diagonal Difference Solution in Java

Diagonal Difference HackerRank Solution in Java

Problem:

Given a square matrix, calculate the absolute difference between the sums of its diagonals.

For example, the square matrix  is shown below:

1 2 3
4 5 6
9 8 9  

The left-to-right diagonal = . The right to left diagonal = . Their absolute difference is .

Function description

Complete the  function in the editor below. It must return an integer representing the absolute diagonal difference.

diagonalDifference takes the following parameter:

• arr: an array of integers .

Input Format

The first line contains a single integer, , the number of rows and columns in the matrix .
Each of the next  lines describes a row, , and consists of  space-separated integers .

Constraints

Output Format

Print the absolute difference between the sums of the matrix's two diagonals as a single integer.

Sample Input

3
11 2 4
4 5 6
10 8 -12

Sample Output

15

Explanation

The primary diagonal is:

11
   5
     -12

Sum across the primary diagonal: 11 + 5 - 12 = 4

The secondary diagonal is:

     4
   5
10

Sum across the secondary diagonal: 4 + 5 + 10 = 19
Difference: |4 - 19| = 15

Note: |x| is the absolute value of x

https://www.hackerrank.com/challenges/diagonal-difference/problem

Diagonal Difference HackerRank Solution in Java 

Diagonal Difference Solution in Java

import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.function.*;
import java.util.regex.*;
import java.util.stream.*;
import static java.util.stream.Collectors.joining;
import static java.util.stream.Collectors.toList;

class Result {
    public static int diagonalDifference(List<List<Integer>> arr) {
    // Write your code here
        int main=0,secondary=0;
        for(int i=0;i<arr.size();i++){
            for(int j=0;j<arr.size();j++){
                if(i==j){
                    main=main+(int)(arr.get(i).get(j));
                    System.out.println(main);
                }
                if(i+j==arr.size()-1)
                {
                    secondary+=(int)(arr.get(i).get(j));
                    System.out.println(secondary);   
                }
            }
        }
        
        if((main-secondary)<0)
            return (main-secondary)*-1;
        else
            return (main-secondary);
}
}
public class Solution {
    public static void main(String[] args) throws IOException {
        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));

        int n = Integer.parseInt(bufferedReader.readLine().trim());

        List<List<Integer>> arr = new ArrayList<>();

        IntStream.range(0, n).forEach(i -> {
            try {
                arr.add(
                    Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
                        .map(Integer::parseInt)
                        .collect(toList())
                );
            } catch (IOException ex) {
                throw new RuntimeException(ex);
            }
        });

        int result = Result.diagonalDifference(arr);

        bufferedWriter.write(String.valueOf(result));
        bufferedWriter.newLine();

        bufferedReader.close();
        bufferedWriter.close();
    }
}