#!/bin/bash

shopt -s dotglob

declare -A leafs=([/]=1)

mapfile -t dirs < <(pacman -Qlq | grep '/$' | sort)
for (( i = 0; i < ${#dirs[*]}; i++ )); do
  dir=${dirs[i]}
  parent=${dir%/*/}/

  if [[ ${leafs["$parent"]} ]]; then
    unset leafs["$parent"]
    continue
  fi

  leafs["$dir"]=1
done

files=()
for l in "${!leafs[@]}"; do
  t=("$l"*)
  [[ -e $t ]] && files+=("${t[@]}")
done

printf '%s\n' "${files[@]}" | grep -vFf <(pacman -Qlq | grep -v '/$')