擅长:python、mysql、java
<p>希望它适用于所有情况:)</p>
<pre><code>s = input()
s_2 = ''.join(sorted(set(s), key=s.index))
sorted_string = sorted(s_2)
str_to_list = list(s_2)
dif = 0
for i in range(len(sorted_string)):
if sorted_string[i]!=str_to_list[i]:
dif+=1
print(dif+abs(len(s)-len(s_2)))
</code></pre>