bash-pure, 420 bytes

Result

WA

Code [DL]

a=()
for((i=0;i<10;i++)); do
read -n 1 c
a+=($c)
done
q(){
   local k i s=() l=()
   p=()
   (($#==0)) && return 0
   k=$1
   shift
   for i; do
      if [[ $i < $k ]]; then
         s+=( "$i" )
      else
         l+=( "$i" )
      fi
   done
   q "${s[@]}"
   s=( "${p[@]}" )
   q "${l[@]}"
   l=( "${p[@]}" )
   p=( "${s[@]}" "$k" "${l[@]}" )
}
q "${a[@]}"
b=$(IFS=;echo "${p[*]}")
echo $b

stdin

1418684016703671735379398472657492580524894017807310803711651819096803527736319161783881565632313622

stdout

stderr

/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
/code.bash: line 2: syntax error near unexpected token `$'do\r''
/code.bash: line 2: `for((i=0;i<10;i++)); do
'

strace