0
CJam, 25 bytes
q~{_L+:L1$a/,3={;][}*}%]p
Takes input from STDIN like
[ 2 1 2 1 0 2 2 1 1 3 4 3]
and outputs like
[[2 1] "" [0 2 2 1 1 3 4] ""]
I am basically iterating over all elements of the array, one by one putting them into another array. Then I get the count of the current element ...