How to generate a list of random numbers without duplicates in pure batch scripting?

Question

I want to generate a list of random numbers with a predefined number of items %RND_TOTAL% in the given range from %RND_MIN% to %RND_MAX%

Answer 1

replace

for /L %%I in (1,1,%RND_TOTAL%) do (
    rem compute a random number:
    set /A "RND_NUM[%%I]=!RANDOM!%%((RND_MAX-RND_MIN)/RND_INTER+1)*RND_INTER+RND_MIN"
    echo !RND_NUM[%%I]!
)

with

for /L %%I in (%rnd_min%,1,%RND_max%) do set "rnd_num{%%I}="
set /a rnd_count=rnd_total
:rnd_loop
rem compute a random number:
set /A "RND_selection=%RANDOM%%%((RND_MAX-RND_MIN)/RND_INTER+1)*RND_INTER+RND_MIN"
if not defined rnd_num{%rnd_selection%} (
 SET "rnd_num{%rnd_selection%}=Y"
 set /a rnd_num[%count%]=rnd_selection
 echo %rnd_selection%
 set /a rnd_count-=1
)
if %rnd_count% neq 0 goto rnd_loop

Each time a selection is made, rnd_num{selectionmade} is set to Y so if it is selected again, it is defined and the recording/output/count-1-less is skipped.