universalShuffleAlgorithm.sol

contract universalShuffleAlgorithm {
    mapping(uint => uint) shuffleIndex;
    uint counter;
    mapping(address => uint) userID;
    uint totalPopulation;
    uint entropy;
    function pickFromHat() {
        uint randomNumber = 1 + getRandomNumber(entropy) % (totalPopulation - 1 - counter);
        if(shuffleIndex[randomNumber] == 0) shuffleIndex[randomNumber] = randomNumber;
        userID[msg.sender] = shuffleIndex[randomNumber];
        if(shuffleIndex[totalPopulation - counter] == 0) shuffleIndex[totalPopulation - counter] = totalPopulation - counter;
        shuffleIndex[randomNumber] = shuffleIndex[totalPopulation - counter];
        counter++;
    }
    function getRandomNumber(uint _entropy) returns (uint) {}
}