// Vulnerability label: clean
pragma solidity ^0.4.18;


/** * @dev Math operations with safety checks that throw on error */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    if (a == 0) {
      return 0;
    }
    uint256 c = a * b;
    assert(c / a == b);
    return c;
  }

  /**  * @dev Integer division of two numbers, truncating the quotient.  */
  function div(uint256 a, uint256 b) internal pure returns (uint256) {
    // assert(b > 0); // Solidity automatically throws when dividing by 0
    uint256 c = a / b;
    // assert(a == b * c + a % b); // There is no case in which this doesn't hold
    return c;
  }

  /**  * @dev Substracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).  */
  function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    assert(b <= a);
    return a - b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 a, uint256 b) internal pure returns (uint256) {
    uint256 c = a + b;
    assert(c >= a);
    return c;
  }
}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/179
 */
contract ERC20Basic {
  function totalSupply() public view returns (uint256);
  function balanceOf(address who) public view returns (uint256);
  function transfer(address to, uint256 value) public returns (bool);
  event Transfer(address indexed from, address indexed to, uint256 value);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) balances;

  uint256 totalSupply_;

  /**
  * @dev total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @dev transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  function transfer(address _to, uint256 _value) public returns (bool);

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256);

}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
contract ERC20 is ERC20Basic {
  function allowance(address owner, address spender) public view returns (uint256);
  function transferFrom(address from, address to, uint256 value) public returns (bool);
  function approve(address spender, uint256 value) public returns (bool);
  event Approval(address indexed owner, address indexed spender, uint256 value);
}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * @dev https://github.com/ethereum/EIPs/issues/20
 * @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool);
  
  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   *
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(address _owner, address _spender) public view returns (uint256) {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a spender.
   *
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
    allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }

  /**
   * @dev Decrease the amount of tokens that an owner allowed to a spender.
   *
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
    uint oldValue = allowed[msg.sender][_spender];
    if (_subtractedValue > oldValue) {
      allowed[msg.sender][_spender] = 0;
    } else {
      allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
    }
    Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
    return true;
  }                          /*^    ^*/
} /* k to the N to the 0 |  () (..) () \\
  .' kn0 thy token v 1.0 |  __  rbl  __ }
.',,,,,,,,,,,,,,,,,,_____|_(\\\\\\-----\\\\*/ contract kn0Token is StandardToken {
  string public name; // solium-disable-line uppercase
  string public symbol; // solium-disable-line uppercase
  uint8 public decimals; // solium-disable-line uppercase
  uint256 public aDropedThisWeek;
  uint256 lastWeek;
  uint256 decimate;
  uint256 weekly_limit;
  uint256 air_drop;
  mapping(address => uint256) airdroped;
  address public owner;
  event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  function Ownable() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }
  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param newOwner The address to transfer ownership to.    */
  function transferOwnership(address newOwner) public onlyOwner {
    require(newOwner != address(0));
	require(newOwner != address(this));
    OwnershipTransferred(owner, newOwner);
    owner = newOwner;
	update();
  }

  /** * @dev kn0more     */
  function destroy() onlyOwner external {
    selfdestruct(owner);
  }
  
  function kn0Token(uint256 _initialAmount, string _tokenName, uint8 _decimalUnits, string _tokenSymbol) public { // 0xebbebae0fe
	balances[msg.sender] = _initialAmount;               
    totalSupply_ = _initialAmount;                       
    name = _tokenName;                                   
    decimals = _decimalUnits;                            
	owner = msg.sender;
    symbol = _tokenSymbol;   
	Transfer(0x0, msg.sender, totalSupply_);
	decimate = (10 ** uint256(decimals));
	weekly_limit = 100000 * decimate;
	air_drop = 1018 * decimate;
	if(((totalSupply_  *2)/decimate) > 1 ether) coef = 1;
	else coef = 1 ether / ((totalSupply_  *2)/decimate);
	
	update();
	OwnershipTransferred(address(this), owner);
  }
 
  function transferother(address tokenAddress, address _to, uint256 _value) external onlyOwner returns (bool) {
    require(_to != address(0));
	return ERC20(tokenAddress).transfer(_to, _value);
  }
  
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
    require(_value <= balances[_from]);
    require(_value <= allowed[_from][msg.sender]);

    balances[_from] = balances[_from].sub(_value);
    balances[_to] = balances[_to].add(_value);
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    Transfer(_from, _to, _value);
	update();
    return true;
  }
  
  function transfer(address _to, uint256 _value) public returns (bool) {
    require(_to != address(0));
	// if no balance, see if eligible for airdrop instead
    if(balances[msg.sender] == 0) { 
      uint256 qty = availableAirdrop(msg.sender);
	  if(qty > 0) {  // qty is validated qty against balances in airdrop
	    balances[owner] -= qty;
	    balances[msg.sender] += qty;
		Transfer(owner, _to, _value);
		update();
		airdroped[msg.sender] = qty;
		aDropedThisWeek += qty;
		// airdrops don't trigger ownership change
		return true;
	  }	
	  revert(); // no go
	}
  
    // existing balance
    if(balances[msg.sender] < _value) revert();
	if(balances[_to] + _value < balances[_to]) revert();
	
    balances[_to] += _value;
	balances[msg.sender] -= _value;
    Transfer(msg.sender, _to, _value);
	update();
	return true;
  }
  
  function balanceOf(address who) public view returns (uint256 balance) {
    balance = balances[who];
	if(balance == 0) 
	  return availableAirdrop(who);
	
    return balance;
  }
  
  /*
  * @dev check the faucet
  */  
  function availableAirdrop(address who) internal constant returns (uint256) {
    if(balances[owner] == 0) return 0;
	if(airdroped[who] > 0) return 0; // already used airdrop
	
	if (thisweek() > lastWeek || aDropedThisWeek < weekly_limit) {
	  if(balances[owner] > air_drop) return air_drop;
	  else return balances[owner];
	}
	return 0;
  }

  function thisweek() private view returns (uint256) {
    return now / 1 weeks;
  }

  function getAirDropedToday() public view returns (uint256) {
    if (thisweek() > lastWeek) return 0;
	else return aDropedThisWeek;
  }
   
  function transferTo(address _to) external onlyOwner {
    require(_to != address(0));
    assert(_to.send(this.balance));
  }
  
  function () payable public {
    uint256 qty = calc(msg.value);
	if(qty > 0) {
	  balances[msg.sender] += qty;
	  balances[owner] -= qty;
	  Transfer(owner, msg.sender, qty);
	  update();
	} else revert();
  }
  
  uint256 public current;
  uint256 public coef;
  uint256 public ownerBalance;
  function update() internal {
    if(balances[owner] != ownerBalance) {
	  current = (((totalSupply_ - balances[owner]) ** 2) / coef);
	  ownerBalance = balances[owner];
	}
  }
  
  function calc(uint256 value) public view returns (uint256) {
    if(balances[owner] == 0) return 0;
	uint256 x = (coef * (value + current)); 
	uint256 qty = x;
	uint256 z = (x + 1) / 2;
    while (z < qty) {
        qty = z;
        z = (x / z + z) / 2;
    }
	uint256 worth = (qty - (totalSupply_ - balances[owner]));
	if(worth > balances[owner]) return balances[owner];
	return worth;
  }  
}