clear
N=input('請輸入信源符號的個數：')	;
for i=1:N
   %data(1).name=input('請輸入各信源符號的名稱：');
   data(i).p=input('請輸入各信源符號發生的概率：');
end
for i=1:N
    pp(i)=data(i).p;   
    data(i).imap=i;     %各符號在編碼過程中的指針
    data(i).Code='';     %各符號的編碼結果 
end
for j = 1:N        % N——信源符號的個數
		for i = 1:N - j
			if (pp(i) > pp(i + 1))
				fT = pp(i);
				pp(i) = pp(i + 1);
				pp(i + 1) = fT;
				for k = 1:N
					if data(k).imap == i
					  data(k).imap = i + 1;
                    elseif data(k).imap == i + 1
						data(k).imap = i;
                    end
                end
            end
        end
    end
	p=pp;
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%// 計算哈夫曼編碼表
	 %// 開始編碼
	for i=1:N-1
        for k = 1:N
			if data(k).imap== i
				data(k).Code = strcat('1',data(k).Code);
               elseif (data(k).imap== i + 1)
			data(k).Code = strcat('0',data(k).Code);
            end
        end       
		p(i + 1) = p(i + 1)+p(i);
		  for k = 1:N
            if (data(k).imap == i)
			data(k).imap = i + 1;
               end
           end
        for j = i + 1:N-1
			if p(j) >p(j + 1)
				fT =p(j);
				p(j) = p(j + 1);
				p(j + 1) = fT;
            	for k = 1:N
				   if (data(k).imap == j)
						data(k).imap = j + 1;
                        elseif (data(k).imap == j + 1)
						data(k).imap = j;
                       end
                end
           end
       end
end