import java.util.*;
public class diagonalDiff {
public static int diagonalDifference(List> arr) {
// Write your code here
// left and right sums; cols = rows = length.arr
// rightSum: 4x4; n = 4; (0,3) (1, 2) (3, 1) (4, 0)
// 3x3, n = 3: right = (0,2) (1,1), (2,0);
// int diff = 0;
int leftSum = 0;
int rightSum = 0;
int n = arr.size();
for (int i = 0; i < n; i++) {
System.out.println("15i: " + i);
for (int j = 0; j < n; j++) {
System.out.println("17j: " + j);
if (i == j) {
System.out.println("18arr.get(i).get(j): " + arr.get(i).get(j));
leftSum += arr.get(i).get(j);
System.out.println("20leftSum: " + leftSum);
}
if (j == n - 1 - i) {
System.out.println("21ij: " + j + ", n-1-i: " + (n - 1 - i));
System.out.println("22arr.get(i).get(j): " + arr.get(i).get(j));
rightSum += arr.get(i).get(j);
System.out.println("26rightSum: " + rightSum);
}
}
}
return Math.abs(leftSum - rightSum);
}
public static void main(String[] args) {
List
> arr = List.of(
List.of(11, 2, 4),
List.of(4, 5, 6),
List.of(10, 8, -12)
);
System.out.println("Output: " + diagonalDifference(arr));
}
}
/*
* https://www.hackerrank.com/challenges/diagonal-difference/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.
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, , the number of rows and columns in the square matrix .
Each of the next lines describes a row, , and consists of space-separated integers .
Constraints
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
*/