SportsToken.sol

pragma solidity 0.4.18;


library SafeMath {
    function mul(uint a, uint b) internal pure returns (uint) {
        uint c = a * b;
        require(a == 0 || c / a == b);
        return c;
    }

    function div(uint a, uint b) internal pure returns (uint) {
        require(b > 0);
        uint c = a / b;
        require(a == b * c + a % b);
        return c;
    }

    function sub(uint a, uint b) internal pure returns (uint) {
        require(b <= a);
        return a - b;
    }

    function add(uint a, uint b) internal pure returns (uint) {
        uint c = a + b;
        require(c >= a);
        return c;
    }

    function max64(uint64 a, uint64 b) internal pure returns (uint64) {
        return a >= b ? a : b;
    }

    function min64(uint64 a, uint64 b) internal pure returns (uint64) {
        return a < b ? a : b;
    }

    function max256(uint256 a, uint256 b) internal pure returns (uint256) {
        return a >= b ? a : b;
    }

    function min256(uint256 a, uint256 b) internal pure returns (uint256) {
        return a < b ? a : b;
    }
}


contract ERC20Basic {
    uint public totalSupply;
    function balanceOf(address who) public view returns (uint);
    function transfer(address to, uint value) public returns (bool);
    event Transfer(address indexed from, address indexed to, uint value);
}


contract ERC20 is ERC20Basic {
    function allowance(address owner, address spender) public view returns (uint);
    function transferFrom(address from, address to, uint value) public returns (bool);
    function approve(address spender, uint value) public returns (bool);
    event Approval(address indexed owner, address indexed spender, uint value);
}


contract BasicToken is ERC20Basic {
    using SafeMath for uint;

    mapping(address => uint) public balances;

    modifier onlyPayloadSize(uint size) {
        if (msg.data.length < size + 4) {
            revert();
        }
        _;
    }

    function transfer(address _to, uint _value)  public onlyPayloadSize(2 * 32) returns (bool) {
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        Transfer(msg.sender, _to, _value);
        return true;
    }

    function balanceOf(address _owner) public view returns (uint balance) {
        return balances[_owner];
    }
}


contract StandardBurnableToken is BasicToken, ERC20 {
    event Burn(address indexed _burner, uint _value);

    function burn(uint _value) public returns (bool) {
        balances[msg.sender] = balances[msg.sender].sub(_value);
        totalSupply = totalSupply.sub(_value);
        Burn(msg.sender, _value);
        Transfer(msg.sender, address(0x0), _value);
        return true;
    }

    // save some gas by making only one contract call
    function burnFrom(address _from, uint256 _value) public returns (bool) {
        transferFrom(_from, msg.sender, _value);
        return burn(_value);
    }
}


contract StandardToken is BasicToken, ERC20 {
    mapping (address => mapping (address => uint)) public allowed;

    function transferFrom(address _from, address _to, uint _value) public returns (bool) {
        var _allowance = allowed[_from][msg.sender];

        // Check is not needed because sub(_allowance, _value) will already revert if this condition is not met
        if (_value > _allowance) revert();

        balances[_to] = balances[_to].add(_value);
        balances[_from] = balances[_from].sub(_value);
        allowed[_from][msg.sender] = _allowance.sub(_value);
        Transfer(_from, _to, _value);
        return true;
    }

    function approve(address _spender, uint _value) public returns (bool) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) public view returns (uint remaining) {
        return allowed[_owner][_spender];
    }
}


contract Zilliqa is StandardToken, StandardBurnableToken {
    string public name = "SportsToken";
    string public symbol = "SPT";
    uint8 public decimals = 12;
    uint public totalSupply = 21 * (10 ** 18);

    function Zilliqa() public {
        balances[msg.sender] = totalSupply;
    }
}