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
Solution:-
<?php
/*
* Complete the 'diagonalDifference' function below.
*
* The function is expected to return an INTEGER.
* The function accepts 2D_INTEGER_ARRAY arr as parameter.
*/
function diagonalDifference($arr) {
// Write your code here
$rightdiagonal=0;
$leftdiagonal=0;
$difference=0;
$n=sizeof($arr);
for($i=0;$i<$n;$i++){
for($j=0;$j<$n;$j++){
if($i==$j){
$leftdiagonal+=$arr[$i][$j];
}
if(($i+$j)==($n-1)){
$rightdiagonal+=$arr[$i][$j];
}
}
}
$difference=abs($rightdiagonal-$leftdiagonal);
return($difference);
}
$fptr = fopen(getenv("OUTPUT_PATH"), "w");
$n = intval(trim(fgets(STDIN)));
$arr = array();
for ($i = 0; $i < $n; $i++) {
$arr_temp = rtrim(fgets(STDIN));
$arr[] = array_map('intval', preg_split('/ /', $arr_temp, -1, PREG_SPLIT_NO_EMPTY));
}
$result = diagonalDifference($arr);
fwrite($fptr, $result . "\n");
fclose($fptr);
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