pragma solidity ^0.4.24;


interface tokenRecipient {

    function receiveApproval(address _from, uint _value, address _token, bytes _extraData) external;

}



contract owned {

    address public owner;

    address public newOwner;



   event OwnershipTransferred(address indexed _from, address indexed _to);



   constructor() owned() public {

        owner = msg.sender;

  

}





 modifier onlyOwner {

        require(msg.sender == owner);

        _;

    }



   function transferOwnership(address _newOwner) onlyOwner public returns (bool success) {

        newOwner = _newOwner;

        return true;

    }



    function acceptOwnership() public returns (bool success) {

        require(msg.sender == newOwner);

        owner = newOwner;

        emit OwnershipTransferred(owner, newOwner);

        newOwner = address(0);

        return true;

    }

}



contract TokenERC20 is owned {

    string public name = 'Worldcoin';

    string public symbol = 'WDT';

    uint8 public decimals = 8;

    uint public totalSupply = 50000000000000;


   mapping (address => uint) public balanceOf;

    mapping (address => mapping (address => uint)) public allowance;

    mapping (address => bool) public frozenAccount;





  event Transfer(address indexed from, address indexed to, uint value);

    event Approval(address indexed _owner, address indexed _spender, uint _value);

    event FrozenFunds(address indexed target, bool frozen);



   constructor() TokenERC20() public {

        balanceOf[msg.sender] = totalSupply;

    }





   function _transfer(address _from, address _to, uint _value) internal {

        require(_to != 0x0);

        require(balanceOf[_from] >= _value);

        require(balanceOf[_to] + _value > balanceOf[_to]);

        require(!frozenAccount[msg.sender]);

        require(!frozenAccount[_from]);

        require(!frozenAccount[_to]);

        

        uint previousBalances = balanceOf[_from] + balanceOf[_to];

        balanceOf[_from] -= _value;

        balanceOf[_to] += _value;

        emit Transfer(_from, _to, _value);

        assert(balanceOf[_from] + balanceOf[_to] == previousBalances);

    }





    function _multipleTransfer(address _from, address[] addresses, uint[] amounts) internal {

        for (uint i=0; i<addresses.length; i++) {

            address _to = addresses[i];

            uint _value = amounts[i];

            _transfer(_from, _to, _value);

        }

    }




    function transfer(address _to, uint _value) public returns (bool success) {

        _transfer(msg.sender, _to, _value);
        return true;

    }




    function multipleTransfer(address[] addresses, uint[] amounts) public returns (bool success) {

        _multipleTransfer(msg.sender, addresses, amounts);

        return true;

    }




    function transferFrom(address _from, address _to, uint _value) public returns (bool success) {

            require(allowance[_from][msg.sender] >= _value);

            allowance[_from][msg.sender] -= _value;
       
            _transfer(_from, _to, _value);

        return true;

    }

    function approveAndCall(address _spender, uint _value, bytes _extraData) public returns (bool success) {

        tokenRecipient spender = tokenRecipient(_spender);

        
            spender.receiveApproval(msg.sender, _value, this, _extraData);
            return true;

        

    }



    function approve(address _spender, uint _value) public returns (bool success) {

        allowance[msg.sender][_spender] = _value;

        emit Approval(msg.sender, _spender, _value);

        return true;

    }



    function freezeAccount(address target, bool freeze) onlyOwner public returns (bool success) {

        frozenAccount[target] = freeze;
        emit FrozenFunds(target, freeze);

        return true;

    }

}