function y=inv(a)
a = rand(5,5);
a = ceil(a);
E=eye(5,5);
 
b = 1;
while a(1,1) == 0;
   a(1,:) =a(1,:) + a(b,:);
   E(1,:) =E(1,:) + E(b,:);
   b = b +1;
end
 
for i=1:row;
E(i,:)=E(i,:)./a(i,i);
a(i,:)=a(i,:)./a(i,i);
for k=i+1:row;
E(k,:)=E(i,:).*a(k,i)-E(k,:);
a(k,:)=a(i,:).*a(k,i)-a(k,:);
end
end
 
for q=1:row;
    for w=q+1:row;
    E(q,:)=E(q,:)-E(w,:).*a(q,w);  
    a(q,:)=a(q,:)-a(w,:).*a(q,w);
    end
end
y=E;

너무 어렵당