In this post, We are going to solve HackerRank Diagonal Difference Problem.
Given a square matrix, calculate the absolute difference between the sums of its diagonals.
For example, the square matrix arr is shown below:
1 2 3
4 5 6
9 8 9 The left-to-right diagonal = 1 + 5 + 9 = 15. The right to left diagonal = 3 + 5 + 9 = 17. Their absolute difference is 15-17 = 2.
Function description
Complete the diagonal difference function in the editor below.
diagonalDifference takes the following parameter:
- int arr[n][m]: an array of integers
Return
- int: the absolute diagonal difference
Input Format
The first line contains a single integer, n, the number of rows and columns in the square matrix arr.
Each of the next n lines describes a row, arr[I], and consists of n space-separated integers arr[I] [j].
Constraints
-100 < arr[I] [j] < 100
Output Format
Return 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
Diagonal Difference C Solution
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>
int main() {
int n;
scanf("%d", &n);
int TlBr = 0;
int TrBl = 0;
int i,j;
int d;
for (i=0; i<n; i++) {
for (j=0; j<n; j++) {
scanf("%d", &d);
if (i==j) TlBr += d;
if ((i+j)==(n-1)) TrBl +=d;
}
}
int sum = TlBr - TrBl;
printf("%d", abs(sum));
return 0;
}Diagonal Difference C++ Solution
#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
/* Enter your code here. Read input from STDIN. Print output to STDOUT */
int n;
int arr[100][100] = {};
cin >> n;
for(int i=0;i<n;i++){
for(int j=0;j<n;j++){
cin >> arr[i][j];
}
}
int sumA=0,sumB=0;
for(int i=0;i<n;i++){
sumA+=arr[i][i];
sumB+=arr[n-i-1][i];
}
cout << abs(sumA-sumB) << endl;
return 0;
}Diagonal Difference C Sharp Solution
using System;
using System.Collections.Generic;
using System.IO;
class Solution {
static void Main(String[] args) {
/* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
int t = Convert.ToInt32(Console.ReadLine());
//var matrixList = new List<int[]>();
var difference = SumOfDifference(t);
Console.WriteLine(difference);
}
private static int SumOfDifference(int t)
{
int diagonal1Sum = 0;
int diagonal2Sum = 0;
for (int i = 0; i < t; i++)
{
// read next line
var elements = Console.ReadLine();
var splitElements = elements.Split(' ');
var row = Array.ConvertAll(splitElements, Convert.ToInt32);
diagonal1Sum += row[i];
diagonal2Sum += row[t - i - 1];
}
int difference = Math.Abs(diagonal1Sum - diagonal2Sum);
return difference;
}
}Diagonal Difference Java Solution
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 {
/*
* Complete the 'diagonalDifference' function below.
*
* The function is expected to return an INTEGER.
* The function accepts 2D_INTEGER_ARRAY arr as parameter.
*/
public static int diagonalDifference(List<List<Integer>> arr) {
// Write your code here
int sum1 = 0;
for(int i = 0; i < arr.size(); i++) {
sum1 += arr.get(i).get(i);
}
int sum2 = 0;
for(int j = 0; j < arr.size(); j++) {
sum2 += arr.get(arr.size()-1-j).get(j);
}
int totalt = sum1-sum2;
if(totalt < 0) {
totalt *= -1;
}
return totalt;
}
}
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();
}
}Diagonal Difference JavaScript Solution
function processData(input) {
var currentLine = 0;
var total = 0;
var leftDiag = 0;
var rightDiag = 0;
inputArray = input.split("\n");
var n = parseInt(inputArray[currentLine].trim(), 10);
var values = inputArray[1].split(' ');
for(var i=0; i<n; i++){
rowValues = inputArray[i+1].split(' ');
leftDiag += parseInt(rowValues[i].trim());
rightDiag += parseInt(rowValues[n-1-i].trim());
}
total = Math.abs(leftDiag-rightDiag);
console.log(total)
}
process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
_input += input;
});
process.stdin.on("end", function () {
processData(_input);
});Diagonal Difference Python Solution
n = int(input())
ar = []
for i in range(n):
ar.append(input().split(" "))
d1 = 0
d2 = 0
for i in range(n):
d1 += int(ar[i][i])
d2 += int(ar[i][-i-1])
print (abs(d1 - d2))Other Solutions
