function result = Markov_Ergodic(P) %轉移矩陣確定Markov鏈是否遍歷的主函數
%
%   隨機數學(30250143, 07Fall) 大作業程序
%
%   作者：葛元愷 2004011425  <geyuank@gmail.com> 
%         王  音 2004011448 <yin-wang04@mails.tsinghua.edu.cn>
%          
%   All rights reserved. 2008.1

[m n] = size(P);

if m~=n,
    error('P must be a square-matrix (m=n)');
end

N = n;
M = 0;
Z = calc_Z(P);

while(2^M < N*(N-1)/2)
    if find(sum(Z)==N) ,
        result = 1;
        return;
    else
        if find(sum(Z)==(N-1)),
            if calc_alpha(Z)>0,
                result = 1;
                return;
            end
        end

        Z = calc_Z(Z*Z);
        M = M+1;
    end
end

if calc_alpha(Z)>0,
    result = 1;
else
    result = 0;
end

return;