题解 | #字符个数统计#

line = input('', 's');
used = [line(1)];
count = 1;
if i > 1
    for i = 2:length(line)
        if used ~= line(i)
            count = count+1;
            used = [used, line(i)];
        end
    end
end
fprintf('%d', count)