杨辉三角形.txt

s11ss写的批处理。他把很多C语言中经典的例子都用批处理实现了

@echo off
setlocal enabledelayedexpansion
::::::::::::::::::::::::::Pascal Triangle  {s11ss 2007-9-26}::::::::::::::::::::::::::
echo Please input the layers:
set/p num=
for /l %%a in (1,1,%num%) do (
        for /l %%i in (1,1,%%a) do (
                set/a x=%%a-1
                set/a y=%%i-1
                set/a n%%a%%i=n!x!!y!+n!x!%%i 
                if %%i equ %%a set n%%a%%i=1
                if %%i equ 1 set/a n%%a%%i=1                
        )
)
for /l %%a in (1,1,%num%) do (
        for /l %%i in (1,1,%%a) do (
                set s%%a=!s%%a!     !n%%a%%i!
        )
)
set fn=%num%_PascalTriangle.txt
set f=
set/p q=Save to the file %fn%?(y/n)
if not "%q%" equ "y" (if not "%q%" equ "Y" goto :e)
cd.>%fn%
set f=^>^>%fn%
:e
for /l %%a in (1,1,%num%) do (
        set/a counter=%num%+1-%%a
        for /l %%i in (1,1,!counter!) do (
                 set s%%a=   !s%%a!
        )
        %f% echo !s%%a!
)
echo.
echo Press Any Key To Exit...
pause>nul