Contract Source Code:

// SPDX-License-Identifier: Unlicensed
pragma solidity ^0.6.12;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */

library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        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;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}


/**
 * @dev Collection of functions related to the address type
 */
library Address {

    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");
    }
}

interface IUniswapV2Factory {
    function createPair(address tokenA, address tokenB) external returns (address pair);
}

interface IUniswapV2Router01 {
    function factory() external pure returns (address);
    function WETH() external pure returns (address);

    function addLiquidity(
        address tokenA,
        address tokenB,
        uint amountADesired,
        uint amountBDesired,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB, uint liquidity);
    function addLiquidityETH(
        address token,
        uint amountTokenDesired,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external payable returns (uint amountToken, uint amountETH, uint liquidity);
    function removeLiquidity(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETH(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountToken, uint amountETH);
    function removeLiquidityWithPermit(
        address tokenA,
        address tokenB,
        uint liquidity,
        uint amountAMin,
        uint amountBMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountA, uint amountB);
    function removeLiquidityETHWithPermit(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountToken, uint amountETH);
    function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapTokensForExactTokens(
        uint amountOut,
        uint amountInMax,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
    function swapExactETHForTokens(uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);
    function swapTokensForExactETH(uint amountOut, uint amountInMax, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapExactTokensForETH(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline)
        external
        returns (uint[] memory amounts);
    function swapETHForExactTokens(uint amountOut, address[] calldata path, address to, uint deadline)
        external
        payable
        returns (uint[] memory amounts);

    function quote(uint amountA, uint reserveA, uint reserveB) external pure returns (uint amountB);
    function getAmountOut(uint amountIn, uint reserveIn, uint reserveOut) external pure returns (uint amountOut);
    function getAmountIn(uint amountOut, uint reserveIn, uint reserveOut) external pure returns (uint amountIn);
    function getAmountsOut(uint amountIn, address[] calldata path) external view returns (uint[] memory amounts);
    function getAmountsIn(uint amountOut, address[] calldata path) external view returns (uint[] memory amounts);
}

interface IUniswapV2Router02 is IUniswapV2Router01 {
    function removeLiquidityETHSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline
    ) external returns (uint amountETH);
    function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens(
        address token,
        uint liquidity,
        uint amountTokenMin,
        uint amountETHMin,
        address to,
        uint deadline,
        bool approveMax, uint8 v, bytes32 r, bytes32 s
    ) external returns (uint amountETH);

    function swapExactTokensForTokensSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
    function swapExactETHForTokensSupportingFeeOnTransferTokens(
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external payable;
    function swapExactTokensForETHSupportingFeeOnTransferTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external;
}


contract YetiCoin {
    using SafeMath for uint256;
    using Address for address payable;

    event Approval(address indexed owner, address indexed spender, uint value);
    event Transfer(address indexed from, address indexed to, uint value);

    mapping (address => uint256) private _rOwned;
    mapping (address => uint256) private _tOwned;
    mapping (address => mapping (address => uint256)) private _allowances;
    mapping (address => bool) private _isExcludedFromFee;

    address public _owner;
    address payable public marketing;
    address payable public development;

    uint256 private constant MAX = ~uint256(0);
    uint256 private _tTotal = 1 * 10**15 * 10**9;
    uint256 private _rTotal = (MAX - (MAX % _tTotal));
    uint256 private _tFeeTotal;

    string private _name = "YetiCoin";
    string private _symbol = "YETIC";
    uint8 private _decimals = 9;

    uint256 public __reflectFee = 1;
    uint256 public __marketingFee = 4;
    uint256 public __developmentFee = 1;
    uint256 public __liquidityFee = 1;
    uint256 public __prev_liquidityFee = 1;

    uint256 public immutable contract_deployed;

    uint256 public _pendingLiquidityFees = 0;

    IUniswapV2Router02 public immutable uniswapV2Router;
    address public immutable uniswapV2Pair;

    bool inSwapAndLiquify;
    bool public swapAndLiquifyEnabled = true;

    uint256 public _maxWalletHolding = 25 * 10**12 * 10**9;
    uint256 private numTokensSellToAddToLiquidity = 9 * 10**12 * 10**9;

    event MinTokensBeforeSwapUpdated(uint256 minTokensBeforeSwap);
    event SwapAndLiquifyEnabledUpdated(bool enabled);
    event SwapAndLiquify(
        uint256 tokensSwapped,
        uint256 ethReceived,
        uint256 tokensIntoLiquidity
    );

    function _msgSender() internal view virtual returns (address payable) {
       return msg.sender;
     }

    modifier onlyOwner() {
       require(_owner == msg.sender, "Caller is not the owner");
       _;
   }

    modifier lockTheSwap {
        inSwapAndLiquify = true;
        _;
        inSwapAndLiquify = false;
    }

    constructor (address payable _marketing, address payable _development) public {
      _owner = msg.sender;
      marketing = _marketing;
      development = _development;
      contract_deployed = block.timestamp;
      _rOwned[msg.sender] = _rTotal;
      IUniswapV2Router02 _uniswapV2Router = IUniswapV2Router02(0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D);
      uniswapV2Router = _uniswapV2Router;
      uniswapV2Pair = IUniswapV2Factory(_uniswapV2Router.factory()).createPair(address(this), _uniswapV2Router.WETH());
      _isExcludedFromFee[msg.sender] = true;
      _isExcludedFromFee[address(this)] = true;
      emit Transfer(address(0), msg.sender, _tTotal);
    }

    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 returns (uint256) {
        return _tTotal;
    }

    function balanceOf(address account) public view returns (uint256) {
        return tokenFromReflection(_rOwned[account]);
    }

    function transfer(address recipient, uint256 amount) public returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

    function approve(address spender, uint256 amount) public returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    function totalFees() public view returns (uint256) {
        return _tFeeTotal;
    }

    function renounceOwnership() public onlyOwner {
        _owner = address(0);
    }

    function reflectionFromToken(uint256 tAmount, bool deductTransferFee) public view returns(uint256) {
        require(tAmount <= _tTotal, "Amount must be less than supply");
        if (!deductTransferFee) {
            (uint256 rAmount,,,,,,) = _getValues(tAmount);
            return rAmount;
        } else {
            (,uint256 rTransferAmount,,,,,) = _getValues(tAmount);
            return rTransferAmount;
        }
    }

    function tokenFromReflection(uint256 rAmount) public view returns(uint256) {
        require(rAmount <= _rTotal, "Amount must be less than total reflections");
        uint256 currentRate =  _getRate();
        return rAmount.div(currentRate);
    }

    //this can be called externally by deployer to immediately process accumulated fees accordingly (distribute to treasury & liquidity)
    function manualSwapAndLiquify() public onlyOwner() {
        uint256 contractTokenBalance = balanceOf(address(this));
        swapAndLiquify(contractTokenBalance);
    }

    function setSwapAndLiquifyEnabled(bool _enabled) public onlyOwner {
        swapAndLiquifyEnabled = _enabled;
        emit SwapAndLiquifyEnabledUpdated(_enabled);
    }

     //to receive ETH from uniswapV2Router when swaping
    receive() external payable {}

    function _reflectFee(uint256 rFee, uint256 tFee) private {
        _rTotal = _rTotal.sub(rFee);
        _tFeeTotal = _tFeeTotal.add(tFee);
    }

    function _getValues(uint256 tAmount) private view returns (uint256, uint256, uint256, uint256, uint256, uint256, uint256) {
        uint256[4] memory tValues = _getTValuesArray(tAmount);
        uint256[3] memory rValues = _getRValuesArray(tAmount, tValues[1], tValues[2], tValues[3]);
        return (rValues[0], rValues[1], rValues[2], tValues[0], tValues[1], tValues[2], tValues[3]);
    }

    function _getTValuesArray(uint256 tAmount) private view returns (uint256[4] memory val) {
        uint256 tFee = calculateTaxFee(tAmount);
        uint256 tLiquidity = calculateLiquidityFee(tAmount);
        uint256 tOperations = calculateOperationsFee(tAmount);
        uint256 tTransferAmount = tAmount.sub(tFee).sub(tLiquidity).sub(tOperations);
        return [tTransferAmount, tFee, tLiquidity, tOperations];
    }

    function _getRValuesArray(uint256 tAmount, uint256 tFee, uint256 tLiquidity, uint256 tOperations) private view returns (uint256[3] memory val) {
        uint256 currentRate = _getRate();
        uint256 rAmount = tAmount.mul(currentRate);
        uint256 rFee = tFee.mul(currentRate);
        uint256 rTransferAmount = rAmount.sub(rFee).sub(tLiquidity.mul(currentRate)).sub(tOperations.mul(currentRate));
        return [rAmount, rTransferAmount, rFee];
    }

    function _getRate() private view returns(uint256) {
        (uint256 rSupply, uint256 tSupply) = _getCurrentSupply();
        return rSupply.div(tSupply);
    }

    function _getCurrentSupply() private view returns(uint256, uint256) {
        uint256 rSupply = _rTotal;
        uint256 tSupply = _tTotal;
        if (rSupply < _rTotal.div(_tTotal)) return (_rTotal, _tTotal);
        return (rSupply, tSupply);
    }

    function _takeLiquidity(uint256 tLiquidity) private {
        uint256 currentRate =  _getRate();
        uint256 rLiquidity = tLiquidity.mul(currentRate);
        _rOwned[address(this)] = _rOwned[address(this)].add(rLiquidity);
        _pendingLiquidityFees = _pendingLiquidityFees.add(tLiquidity);
    }

    function _takeOperations(uint256 tOperations) private {
        uint256 currentRate =  _getRate();
        uint256 rOperations = tOperations.mul(currentRate);
        _rOwned[address(this)] = _rOwned[address(this)].add(rOperations);
    }

    function calculateTaxFee(uint256 _amount) private view returns (uint256) {
        return _amount.mul(__reflectFee).div(
            10**2
        );
    }

    function calculateLiquidityFee(uint256 _amount) private view returns (uint256) {
        return _amount.mul(__liquidityFee).div(
            10**2
        );
    }

    function calculateOperationsFee(uint256 _amount) private view returns (uint256) {
        uint256 operations_fee = __marketingFee.add(__developmentFee);
        return _amount.mul(operations_fee).div(
            10**2
        );
    }

    function removeAllFee() private {
        __prev_liquidityFee = __liquidityFee;

        __reflectFee = 0;
        __liquidityFee = 0;
        __marketingFee = 0;
        __developmentFee = 0;
    }

    function restoreAllFee() private {
        __reflectFee = 1;
        __liquidityFee = __prev_liquidityFee;
        __marketingFee = 4;
        __developmentFee = 1;
    }

    function isExcludedFromFee(address account) public view returns(bool) {
        return _isExcludedFromFee[account];
    }

    function _approve(address owner, address spender, uint256 amount) private {
        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 _transfer(
        address from,
        address to,
        uint256 amount
    ) private {
        require(from != address(0), "ERC20: transfer from the zero address");
        require(to != address(0), "ERC20: transfer to the zero address");
        require(amount > 0, "Transfer amount must be greater than zero");
        if ((contract_deployed + 30 days) < block.timestamp) {
          __liquidityFee = 0;
          __prev_liquidityFee = 0;
        }

        uint256 contractTokenBalance = balanceOf(address(this));

        bool overMinTokenBalance = contractTokenBalance >= numTokensSellToAddToLiquidity;
        if (
            overMinTokenBalance &&
            !inSwapAndLiquify &&
            from != uniswapV2Pair &&
            swapAndLiquifyEnabled
        ) {
            swapAndLiquify(contractTokenBalance);
        }

        //indicates if fee should be deducted from transfer
        bool takeFee = true;

        //if any account belongs to _isExcludedFromFee account then remove the fee
        if(_isExcludedFromFee[from] || _isExcludedFromFee[to]){
            takeFee = false;
        }

        bool isTransferBuy = from == uniswapV2Pair;
        bool isTransferSell = to == uniswapV2Pair;
        if (!isTransferBuy && !isTransferSell) takeFee = false;

        _tokenTransfer(from,to,amount,takeFee);

        restoreAllFee();
    }

    function swapAndLiquify(uint256 contractTokenBalance) private lockTheSwap {
        uint256 liquidityPart = 0;
        if (_pendingLiquidityFees < contractTokenBalance) liquidityPart = _pendingLiquidityFees;
        uint256 distributionPart = contractTokenBalance.sub(liquidityPart);
        uint256 liquidityHalfPart = liquidityPart.div(2);
        uint256 liquidityHalfTokenPart = liquidityPart.sub(liquidityHalfPart);

        //now swapping half of the liquidity part + all of the distribution part into ETH
        uint256 totalETHSwap = liquidityHalfPart.add(distributionPart);

        uint256 initialBalance = address(this).balance;

        // swap tokens for ETH
        swapTokensForEth(totalETHSwap);

        uint256 newBalance = address(this).balance.sub(initialBalance);
        uint256 liquidityBalance = liquidityHalfPart.mul(newBalance).div(totalETHSwap);

        // add liquidity to uniswap
        if (liquidityHalfTokenPart > 0 && liquidityBalance > 0) addLiquidity(liquidityHalfTokenPart, liquidityBalance);
        emit SwapAndLiquify(liquidityHalfPart, liquidityBalance, liquidityHalfPart);

        newBalance = address(this).balance;
        payDistribution(newBalance);
        _pendingLiquidityFees = 0;
    }

    function swapTokensForEth(uint256 tokenAmount) private {
        // generate the uniswap pair path of token -> weth
        address[] memory path = new address[](2);
        path[0] = address(this);
        path[1] = uniswapV2Router.WETH();

        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // make the swap
        uniswapV2Router.swapExactTokensForETHSupportingFeeOnTransferTokens(
            tokenAmount,
            0, // accept any amount of ETH
            path,
            address(this),
            block.timestamp
        );
    }

    function addLiquidity(uint256 tokenAmount, uint256 ethAmount) private {
        // approve token transfer to cover all possible scenarios
        _approve(address(this), address(uniswapV2Router), tokenAmount);

        // add the liquidity
        uniswapV2Router.addLiquidityETH{value: ethAmount}(
            address(this),
            tokenAmount,
            0, // slippage is unavoidable
            0, // slippage is unavoidable
            marketing,
            block.timestamp
        );
    }

    function payDistribution(uint256 distrib) private {
      uint256 marketingPart = distrib.mul(__marketingFee).div(__marketingFee.add(__developmentFee));
      marketing.sendValue(marketingPart);
      development.sendValue(distrib.sub(marketingPart));
    }

    //this method is responsible for taking all fee, if takeFee is true
    function _tokenTransfer(address sender, address recipient, uint256 amount,bool takeFee) private {
        if(!takeFee) removeAllFee();
        _transferStandard(sender, recipient, amount);
        if (!_isExcludedFromFee[recipient] && (recipient != uniswapV2Pair)) require(balanceOf(recipient) < _maxWalletHolding, "Max Wallet holding limit exceeded");
    }

    function _transferStandard(address sender, address recipient, uint256 tAmount) private {
        (uint256 rAmount, uint256 rTransferAmount, uint256 rFee, uint256 tTransferAmount, uint256 tFee, uint256 tLiquidity, uint256 tOperations) = _getValues(tAmount);
        _rOwned[sender] = _rOwned[sender].sub(rAmount);
        _rOwned[recipient] = _rOwned[recipient].add(rTransferAmount);
        _takeLiquidity(tLiquidity);
        _takeOperations(tOperations);
        _reflectFee(rFee, tFee);
        emit Transfer(sender, recipient, tTransferAmount);
    }

}