Implement batch processing code that outputs two texts in parallel

There are two texts as follows (the actual number of lines of the two texts is unknown ):

20171.txt

Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Ccccccccccccccccccccccccccccccccccccccccccc
Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Ggggggggggggggggggggggggggggggggggggggg
Wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

20172.txt

Hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
Iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
Bytes

Batch output is required as follows (two texts are output alternately ):

Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh
Ccccccccccccccccccccccccccccccccccccccccccc
Iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii
Eeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
Bytes
Ggggggggggggggggggggggggggggggggggggggg

Wwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwwww
Zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz

Requirements:
1. Try not to generate temporary files
2 code efficiency
3. Code as concise as possible
Purpose:
The only purpose is to improve together!

Answer:
More:Copy codeThe Code is as follows: @ echo off
Setlocal enabledelayedexpansion
For/f "delims =" % a in ('Type 11.txt ') do (
Set/a m + = 1
Set "home! M! = %"
)
For/f "delims =" % B in ('Type 12.txt ') do (
Set/a n + = 1
Set "bat! N! = % B"
)
If % m % gtr % n % (
For/l % c in (1 1% m %) do (
If not "! Home % c! "=" "Echo! Home % c!
If not "! Bat % c! "=" "Echo! Bat % c!
)
) Else (
For/l % d in (1 1% n %) do (
If not "! Home % d! "=" "Echo! Home % d!
If not "! Bat % d! "=" "Echo! Bat % d!
)
)
Pause

　

Batman:Copy codeThe Code is as follows: @ echo off
For/f "delims =" % I in (1.txt) do set/a n + = 1 & call, set "_ % n % = % I"
For/f "delims =" % I in (2.txt) do set/a m + = 1 & call, set ". % m % = % I"
If % n % gtr % m % (set "num = % n %") else (set "num = % m % ")
For/l % I in (1, 1, % num %) do (
If defined _ % I call, echo % _ % I %
If defined. % I call, echo %. % I %
)
Pause> nul

　

Pusofalse:Copy codeThe Code is as follows: @ echo off & setlocal enabledelayedexpansion & set n =-1
For/f "delims =" % a in (1.txt) do (
Set/a n + = 1
Set flag =
Call: lp %
If not defined flag echo %
)
: Lp
If "% 1" equ "" set/a n + = 1
Set m = skip = % n %
If "% m %" equ "skip = 0" set "m ="
For/f "% m % delims =" % a in (2.txt) do if "% 1" neq "" (echo % 1 & echo % a & set flag = a & goto: eof) else echo %
If "% 1" equ "" pause

　

Batman:Copy codeThe Code is as follows: @ echo off
Set "n =-1" & set "flag ="
: Begin
Set/a n + = 1
If % n % equ 0 (set "m =") else (set "m = skip = % n % ")
For/f "% m % delims =" % I in (1.txt) do echo % I & if defined flag goto next
Set no =
: Next
For/f "% m % delims =" % I in (2.txt) do echo % I & goto begin
If not defined no set "flag =" & goto begin
Pause> nul

　

Batman:Copy codeThe Code is as follows: @ echo off & setlocal enabledelayedexpansion
Set "num = 0"
For % a in (1.txt 2.txt) do (
For/f "delims =" % I in (% a) do (
Set/a n + = 1
If! N! Gtr! Num! Set "num =! N! "
Set/p = % I <nul> temp.txt
)
Echo.> temp.txt & set "n = 0"
)
: Lp
Set/a n + = 1
For/f "tokens = % n %" % I in (temp.txt) do echo % I
If % n % neq % num % goto lp
Del/q temp.txt & pause> nul