Task

Find and display the sum of elements that are below the main diagonal of a matrix.

The matrix should be a square matrix.



 ───   Matrix to be used:   ───


     [[1,3,7,8,10],
      [2,4,16,14,4],
      [3,1,9,18,11],
      [12,14,17,18,20],
      [7,1,3,9,5]] 



arraybase 1
dim diag = {{ 1, 3, 7, 8,10}, { 2, 4,16,14, 4}, { 3, 1, 9,18,11}, {12,14,17,18,20}, { 7, 1, 3, 9, 5}}
ind = diag[?,]
sumDiag = 0
 
for x = 1 to diag[?,]
	for y = 1 to diag[,?]-ind
		sumDiag += diag[x, y]
	next y
	ind -= 1
next x
 
print "Sum of elements below main diagonal of matrix is "; sumDiag
end