[mathjiang]

function bibao=qiubb(x)
% 函数名 qiubb=求方阵x的闭包;
% 求闭包的方法：平方法(取大取小);
% 调用格式：bibao=qiubb(x);
[m, n]=size(x);
if m ~= n
disp('输入的矩阵不是方阵');
return
end

xsquare=qiupf(x);

while sum(sum(x==xsquare))~=n^2
x=xsquare;
xsquare=qiupf(x);
end
bibao=xsquare;