中国DOS联盟

@echo off&setlocal enabledelayedexpansion
set/a n=5000
set s=1
:lp
set str=&set p=
for /l %%i in (!s! 1 !n!) do (
    if not defined %%i (
    set/a m+=1,t=m%%3
    if !t! equ 0 (set %%i=%%i) else (
    if not defined p set s=%%i
    set str=!str! %%i&set/a p+=1&set u=%%i
)))
if !p! gtr 1 set n=!u!&goto lp
echo 最后剩下的是原来的 !str! 号
pause

@echo off
set /p a=please input data:
set b=%a%
:lp1
set /a n+=1&set a=%a:~1%
if defined a goto :lp1
:lp2
set/a n-=1&set loop1=%b:~0,2%&set loop2=%b:~3%
set b=%loop2%%loop1%
if %n% equ 3 (echo the last number is: %b:~1,1%) else (goto :lp2) 
pause