% Is a matrix strictly diagonally dominant
% CONVERT THIS TO A FUNCTION exactly ASKED FOR in the problem statement
clc
A=[12  3  4; 4  -12  6;  12   12  25]
% size of matrix
n=length(A)
% count used as a counter as for how many rows the inequality is met
count=0
for i=1:1:n
% finding the right hand side of the inequality
    sum=0
    for j=1:1:n
        if i~=j 
            sum=sum+abs(A(i,j))
        end
    end
% Comparing the LHS and RHS of inequality
  if abs(A(i,i))>sum
   count=count+1
  end
end

% If the inequality is satisfied for all rows then the matrix is strictly
% diagonaly dominant, else it is not strictly diagonally dominant.
if count==n 
    fprintf('Strictly diagonally dominant')
else
    fprintf('Not strictly diagonally dominant')
end