detect QuickFix window list or LocationList

I want to bind key Alt-n/p to next/previous LocationList or next/previous QuickFix list.
So I need to detect which List in current buffer. then bind Alt-n/p to them.
like this.
if (detect Location or QuickFix)
map <A-n> :cnext<CR>
map <A-n> :cprevious<CR>
elseif
map <A-n> :lnext<CR>
map <A-n> :lprevious<CR>
endif

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