@echo off
setlocal enabledelayedexpansion

    %== Initialization ==%
set "male= abe bob col dan ed fred gav hal ian jon" ::First whitespace is necessary
set "female= abi bea cath dee eve fay gay hope ivy jan" ::same here...

    ::Initialization of pseudo-arrays [Male]
set "cnt=0" & for %%. in (abi, eve, cath, ivy, jan, dee, fay, bea, hope, gay) do (set abe[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (cath, hope, abi, dee, eve, fay, bea, jan, ivy, gay) do (set bob[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (hope, eve, abi, dee, bea, fay, ivy, gay, cath, jan) do (set col[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (ivy, fay, dee, gay, hope, eve, jan, bea, cath, abi) do (set dan[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (jan, dee, bea, cath, fay, eve, abi, ivy, hope, gay) do (set ed[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (bea, abi, dee, gay, eve, ivy, cath, jan, hope, fay) do (set fred[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (gay, eve, ivy, bea, cath, abi, dee, hope, jan, fay) do (set gav[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (abi, eve, hope, fay, ivy, cath, jan, bea, gay, dee) do (set hal[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (hope, cath, dee, gay, bea, abi, fay, ivy, jan, eve) do (set ian[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (abi, fay, jan, gay, eve, bea, dee, cath, ivy, hope) do (set jon[!cnt!]=%%.&set /a cnt+=1)

    ::Initialization of pseudo-arrays [Female]
set "cnt=0" & for %%. in (bob, fred, jon, gav, ian, abe, dan, ed, col, hal) do (set abi[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (bob, abe, col, fred, gav, dan, ian, ed, jon, hal) do (set bea[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (fred, bob, ed, gav, hal, col, ian, abe, dan, jon) do (set cath[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (fred, jon, col, abe, ian, hal, gav, dan, bob, ed) do (set dee[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (jon, hal, fred, dan, abe, gav, col, ed, ian, bob) do (set eve[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (bob, abe, ed, ian, jon, dan, fred, gav, col, hal) do (set fay[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (jon, gav, hal, fred, bob, abe, col, ed, dan, ian) do (set gay[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (gav, jon, bob, abe, ian, dan, hal, ed, col, fred) do (set hope[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (ian, col, hal, gav, fred, bob, abe, ed, jon, dan) do (set ivy[!cnt!]=%%.&set /a cnt+=1)
set "cnt=0" & for %%. in (ed, hal, gav, abe, bob, jon, col, ian, fred, dan) do (set jan[!cnt!]=%%.&set /a cnt+=1)
    %==/Initialization ==%

(   %== The main thing ==%
echo.HISTORY:
call :stableMatching
echo.
echo.NEWLYWEDS:
call :display
echo.
call :isStable
echo.
echo.What if ed and hal swapped?
call :swapper ed hal
echo.
echo.NEW-NEWLYWEDS:
call :display
echo.
call :isStable
pause>nul
exit /b 0
)   %==/The main thing ==%

    %== The algorithm ==%
:stableMatching
    set "free_men=%male%"       ::The free-men variable
    set "free_women=%female%"   ::The free-women variable
    set nextgirl=0
:thematchloop
    set m=&for %%F in (!free_men!) do (if not defined m set "m=%%F")
    if "!m!"=="" goto :EOF

    for /f "tokens=1-2 delims==" %%A in ('set !m![!nextgirl!]') do set "w=%%B"
    set "propo="
    for %%W in (!free_women!) do (
        if "%%W"=="!w!" (
            set propo=TRUE
            set "!w!_=!m!" & set "!m!_=!w!"
            set free_women=!free_women: %w%=!
            set free_men=!free_men: %m%=!
            echo.   !w! ACCEPTED !m!.
        )
    )
    if defined propo (set "nextgirl=0" & goto thematchloop)

    for /f "tokens=1-2 delims==" %%A in ('set !w!_') do set "mbef=%%B"
    set "replace=" & for /f "tokens=1-2 delims==" %%R in ('set !w![') do (
        if not defined replace (
            if "%%S"=="!m!" (
                set replace=TRUE
                set "!w!_=!m!" & set "!m!_=!w!"
                set "free_men=!free_men! !mbef!"
                set "free_men=!free_men: %m%=!"
                set nextgirl=0
                echo.   !w! LEFT !mbef!.
                echo.   !w! ACCEPTED !m!.
            )
            if "%%S"=="!mbef!" (
                set /a nextgirl+=1
                set replace=FALSE
            )
        )
    )
goto thematchloop
    %==/The Algorithm ==%

    %== Output the Couples ==%
:display
for %%S in (!male!) do echo.    %%S and !%%S_!.
goto :EOF
    %==/Output the Couples ==%

    %== Stability Checking ==%
:isStable
for %%M in (!female!) do (
    set "better="
    set "dislike=" & for /f "tokens=1-2 delims==" %%R in ('set %%M[') do (
        if not defined dislike (
            if "%%S"=="!%%M_!" (set dislike=T) else (set "better=!better! %%S")
        )
    )
    for %%X in (!better!) do (
        for /f "tokens=1-2 delims==" %%F in ('set %%X_') do set curr_partner_of_boy=%%G
        set "main_check="
        for /f "tokens=1-2 delims==" %%B in ('set %%X[') do (
            if not defined main_check (
                if "%%C"=="%%M" (
                    echo.STABILITY = FALSE.
                    echo %%M and %%X would rather be together than their current partners.
                    goto :EOF
                )
                if "%%C"=="!curr_partner_of_boy!" set "main_check=CONTINUE"
            )
        )
    )
)
echo.STABILITY = TRUE.
goto :EOF
    %==/Stability Chacking ==%

    %== Swapper ==%
:swapper
    set %~1.tmp=!%~1_!
    set %~2.tmp=!%~2_!
    set "%~1_=!%~2.tmp!"
    set "%~2_=!%~1.tmp!"
    set "!%~1.tmp!_=%~2"
    set "!%~2.tmp!_=%~1"
    goto :EOF
    %==/Swapper==%