hackerRank - Diagonal Difference
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 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 greater than equal to arr[i][j] greater than equal to 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