Absolute diagonal difference algorithms

1. diagonal_difference_1

Step 1 Use two nested loops to iterate on matrix elements.
Step 2 If counters match add the value at the array index to first diagonal sum.
            If first counter matches the operation below add the value at the array index to second diagonal sum.
Step 3 Find the difference between first diagonal and the second diagonal.
Step 4 Return the absolute value of the difference.

ALGORITHM
diagonal_difference_1(int **a, int size)

//Computes absolute diagonal difference
//Input: 2d array of integers, size of the square matrix
//Output: absolute diagonal differnce of the matrix a

for i <- 0 to size do
	for j <- to size do
		if (i == j)
			first_diagonal <- first_diagonal + a[i][j]
		if (i == size - j - 1)
			second_diagonal <- second_diagonal + a[i][j]

difference = first_diagonal - second_diagonal
return abs(difference)

2. diagonal_difference_2

Step 1 Use one loop to iterate on the matrix elements.
Step 2 Knowing the indices of the first and second diagonal compute sum.
Step 3 Find the difference between first diagonal and the second diagonal.
Step 4 Return the absolute value of the difference.

ALGORITHM
diagonal_difference_2(int **a, int size)

//Computes absolute diagonal difference
//Input: 2d array of integers, size of the square matrix
//Output: absolute diagonal differnce of the matrix a

for i <- 0 to size do
	first_diagonal <- first_diagonal + a[i][i]
	second_diagonal <- second_diagonal + a[size - i - 1][i]

difference = first_diagonal - second_diagonal
return abs(difference)