Binary search: Difference between revisions

=={{header|Batch File}}==

<lang windowsnt>

@echo off & setlocal enabledelayedexpansion

:: Binary Chop Algorithm - Michael Sanders 2017

::

:: example output...

::

:: binary chop algorithm vs. standard for loop

::

:: number to find 941

:: for loop required 941 iterations

:: binchop required 10 iterations

:setup

set x=1

set y=999

set /a z=(%random% * (%y% - 1) / 32768 + 1)

:pseudoarray

for /l %%q in (%x%,1,%y%) do set /a array[%%q]=%%q

:std4loop

for /l %%q in (%x%,1,%y%) do (

if !array[%%q]!==%z% (set f=%%q& goto :binchop)

)

:binchop

if !x! leq !y! (

set /a i+=1

set /a "p=(!x!+!y!)/2"

call set /a t=%%array[!p!]%%

if !t! equ !z! (set b=!i!& goto :done)

if !t! lss !z! (set /a x=!p!+1) else (set /a y=!p!-1)

goto :binchop

)

:done

cls

echo binary chop algorithm vs. standard for loop...

echo.

echo . number to find !z!

echo . for loop required !f! iterations

echo . binchop required !b! iterations

endlocal & exit /b 0

</lang>