%
% create_A_b.m
%
given_case = 4;

if (given_case == 0)
A = [ 1 0 1;
      0 0 0;
      0 1 1 ];
b = [ 1 ;
      2 ;
      3 ];
elseif (given_case == 1)
A = [ 0 1 0;
      0 0 1;
      0 0 1 ];
b = [ 1 ;
      2 ;
      3 ];
elseif (given_case == 2)
A = [ 0 1 0;
      0 0 1;
      0 0 1 ];
b = [ 1 ;
      3 ;
      3 ];
elseif (given_case == 3)
A = [ 0 0 1;
      1 0 0;
      0 1 0 ];
b = [ 1 ;
      2 ;
      3 ];
elseif (given_case == 4)
A = [ 1 1 1 0 ;
      0 0 0 0 ;
      0 0 1 1 ;
      0 0 1 1 ];
b = [ 1 ;
      0 ;
      2 ;
      3 ];
elseif (given_case == 5)
A = [ 1 1 1 1 ;
      0 0 1 1 ;
      0 0 1 1 ;
      0 0 1 1 ];
b = [ 1 ;
      3 ;
      3 ;
      3 ];
elseif (given_case == 9)
 A=-ones(n,n) + tril(ones(n,n)) + diag(ones(n,1)); 
 x = (1./(1:n))';
 b = A*x;
end
 %