ref. http://npnl.hatenablog.jp/entry/2013/01/27/084249

trumpDistribution.groovy

String[] deal(int numPlayers, String deck) {
  deck.toList().collate(numPlayers, false)
    .transpose()*.join() ?: [''] * numPlayers
}
assert deal(3, '123123123') == ['111', '222', '333'] as String[]
assert deal(4, '123123123') == ['12', '23', '31', '12'] as String[]
assert deal(6, '012345012345012345') == ['000', '111', '222', '333', '444', '555'] as String[]
assert deal(4, '111122223333') == ['123', '123', '123', '123'] as String[]
assert deal(1, '012345012345012345') == ['012345012345012345'] as String[]
assert deal(6, '01234') == ['', '', '', '', '', ''] as String[]
assert deal(2, '') == ['', ''] as String[]