BS0小陈

@echo off
SETLOCAL ENABLEDELAYEDEXPANSION
set /p n=请输入不多于20个的字母：
for /l %%b in (0 1 20) do (
set k=
for %%a in (aA bB cC dD eE fF gG hH iI jJ kK lL mM nN oO pP qQ rR sS tT uU 

vV wW xX yY zZ) do (
set b=%%a
set ba=!b:~0,1!
set bb=!b:~1,1!
set c=!n:~%%b,1!
if "!c!"=="" goto end
if !c!==!ba! set k=!bb!
if !c!==!bb! set k=!ba!
)
if "!k!"="" set k=!c!
set /p=!k!<nul
)
:end
pause>nul
复制代码

错在哪里了啊，去掉最后一个if就行了可是那样对于非字母就~~~