The BackPacker

Determinates a player that has won the most, yet and chooses his last vote.

public class BackPacker extends Human {
    public String takeSides(String history)  {
        if (history == null || history.equals(""))
            return "evil";
        String[] roundVotes = history.split(",");
        int players = roundVotes[0].length();
        int[] winningPlayers = new int[players];
        for (int round = 0; round < roundVotes.length; round++) {
            String nextRound = roundVotes[round];
            boolean didGoodWin = didGoodWin(nextRound, players);
            for (int player = 0; player < nextRound.length(); player++) {
                boolean good = nextRound.charAt(player) == '1';
                winningPlayers[player] += ((!didGoodWin && good) || (didGoodWin && !good)) ? 1 : 0;
            }
        }
        int bestScore = -1;
        for (int nextPlayer : winningPlayers)
            if (bestScore < nextPlayer)
                bestScore = nextPlayer;
        int bestPlayer = 0;
        for (int ii = 0; ii < players; ii++) {
            if (winningPlayers[ii] == bestScore) {
                bestPlayer = ii;
                break;
            }
        }
        if (roundVotes[roundVotes.length - 1].charAt(bestPlayer) == '1')
            return "good";
        return "evil";
    }

    private boolean didGoodWin(String round, int players) {
        int good = 0;
        for (char next : round.toCharArray())
            good += next == '1' ? 1 : 0;
        return (good * 2) > players;
    }
}