X = [1 2 3 4; 5 6 7 8; 2 3 4 5; 5 6 4 3; 2 1 0 2];
Y = [0; 4; 7; 9; 0];

%(a)
X(2,3) = -1;
disp(X);

%(b)
Z = X;
Z(2,:) = []; % 刪除第二列
Z(:,3) = []; % 刪除第三行
disp(Z);

%(c)
X = [X Y];
disp(X);

%(d)
[rows, cols] = size(X);
n = min(rows, cols);
for i = 1:n
    X(i,i) = 0;
end
disp(X);