Algorithm
Problem Name: Algorithms -
In this HackerRank Functions in Algorithms - Java programming problem solution,
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 = 1 + 5 + 9 = 15. The right to left diagonal = 3 + 5 + 9 = 17. Their absolute difference is |15 - 17| = 2
Function description
Complete the diagonalDifference 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
Note: |x| is the absolute value of x
Code Examples
#1 Code Example with C Programming
Code -
C Programming
#include <stdio.h>
#include <stdlib.h>
int main() {
int n, k;
scanf("%d", &n);
int total = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < n; j++) {
scanf("%d", &k);
if (i == j)
total += k;
if (i == n - j - 1)
total -= k;
}
}
printf("%d", abs(total));
return 0;
}
#2 Code Example with C++ Programming
Code -
C++ Programming
#include <bits/stdc++.h>
using namespace std;
string ltrim(const string &);
string rtrim(const string &);
vector < string> split(const string &);
/*
* Complete the 'diagonalDifference' function below.
*
* The function is expected to return an INTEGER.
* The function accepts 2D_INTEGER_ARRAY arr as parameter.
*/
int diagonalDifference(vector<vector<int>> arr) {
int s1 = 0;
int s2 = 0;
int n = arr.size();
for(int i = 0; i < n; i++) {
s1 += arr[i][i];
s2 += arr[i][n-i-1];
}
return abs(s1 - s2);
}
int main()
{
ofstream fout(getenv("OUTPUT_PATH"));
string n_temp;
getline(cin, n_temp);
int n = stoi(ltrim(rtrim(n_temp)));
vector < vector<int>> arr(n);
for (int i = 0; i < n; i++) {
arr[i].resize(n);
string arr_row_temp_temp;
getline(cin, arr_row_temp_temp);
vector < string> arr_row_temp = split(rtrim(arr_row_temp_temp));
for (int j = 0; j < n; j++) {
int arr_row_item = stoi(arr_row_temp[j]);
arr[i][j] = arr_row_item;
}
}
int result = diagonalDifference(arr);
fout << result << "\n";
fout.close();
return 0;
}
string ltrim(const string &str) {
string s(str);
s.erase(
s.begin(),
find_if(s.begin(), s.end(), not1(ptr_fun < int, int>(isspace)))
);
return s;
}
string rtrim(const string &str) {
string s(str);
s.erase(
find_if(s.rbegin(), s.rend(), not1(ptr_fun < int, int>(isspace))).base(),
s.end()
);
return s;
}
vector < string> split(const string &str) {
vector<string> tokens;
string::size_type start = 0;
string::size_type end = 0;
while ((end = str.find(" ", start)) != string::npos) {
tokens.push_back(str.substr(start, end - start));
start = end + 1;
}
tokens.push_back(str.substr(start));
return tokens;
}
#3 Code Example with Java Programming
Code -
Java Programming
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 b) ? a - b : b - a;
}
}
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();
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();
}
}
#4 Code Example with C# Programming
Code -
C# Programming
using System;
using static System.Console;
class Solution
{
static void Main(String[] args)
{
var sumPrimaryDiagonal = 0;
var sumSecondaryDiagonal = 0;
var n = int.Parse(ReadLine());
for (int i = 0, j = n - 1; i < n; i++, j--)
{
var a_temp = ReadLine().Split(' ');
var newRow = Array.ConvertAll(a_temp, int.Parse);
sumPrimaryDiagonal += newRow[i];
sumSecondaryDiagonal += newRow[j];
}
WriteLine(Math.Abs(sumPrimaryDiagonal - sumSecondaryDiagonal));
}
}
#5 Code Example with Python Programming
Code -
Python Programming
import math
import os
import random
import re
import sys
# Complete the diagonalDifference function below.
def diagonalDifference(arr):
prim =0
sec=0
length = len(arr[0])
for count in range(length):
prim += arr[count][count]
sec += arr[count][(length-count-1)]
return abs(prim-sec)
if __name__ == '__main__':
fptr = open(os.environ['OUTPUT_PATH'], 'w')
n = int(input())
arr = []
for _ in range(n):
arr.append(list(map(int, input().rstrip().split())))
result = diagonalDifference(arr)
fptr.write(str(result) + '\n')
fptr.close()