筛选质数.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
::::::::::::::::::::::::::::Find Prime Numbers::::::::::::::::::::::::::::
::::::::::::::::::::::::::::{s11ss  2007-9-20}::::::::::::::::::::::::::::
:r
echo Please input the upper limit number:
set /p n=
if not !n! geq 2 (echo 2 at least. & goto :r)
set /a i=2
:ci
set /a j=!i!
:cj
set /a m=!i!*!j!
if !m! leq !n! (
        set /a j+=1
        ::set /a counter+=1
        set m!m!=1
        goto :cj
) else (
        set /a i+=1
        set /a ii=!i!*!i!
        if !ii! leq !n! (goto :ci) else (goto :e)
)
:e
set s=
for /l %%a in (2,1,!n!) do (
        if !m%%a! equ 1 (
                set s=%%a !s!
        )
) 
set /a counter=0
echo.
echo In [2,!n!],prime numbers are:
for /l %%a in (2,1,!n!) do (
        set isprime=True
        set prime=%%a
        for %%b in (!s!) do (
                if !prime! equ %%b set isprime=False
        )
        if !isprime! equ True (
                echo !prime!
                set /a counter+=1
        )
)
echo.
echo In total:!counter!
echo.
echo Press Any Key To Exit.
pause>nul