CRD-Deflationary-Token

pragma solidity ^0.6.12;

// SPDX-License-Identifier: MIT

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);

event Burn(address indexed from, uint256 value);

}

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) {
    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;
}

}

contract CDR is IERC20 {

    using SafeMath for uint256;

string internal _name;
string internal _symbol;
uint8 internal _decimals;
uint256 internal _totalSupply;
uint8 internal _brate;



address internal  _admin;


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


constructor() public {
    _admin = msg.sender;
    _symbol = "CDR";  
    _name = "CDR"; 
    _decimals = 18;
    _brate = 2;  
    _totalSupply = 1102500000* 10**uint(_decimals);
    balances[msg.sender]=_totalSupply;
   
}






function changeBurnRate(uint8 brate) public {
     require(msg.sender==_admin);
       _brate = brate;      

}

 function brate() public view returns (uint8) 
{
    return _brate;
}

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 _to, uint256 _value) public virtual override returns (bool) {

 require(_to != address(0) && _value > 0);

    uint burn_token = (_value*_brate)/100;
    require(_value+burn_token > _value);

    require(_value + burn_token <= balances[msg.sender]);
    balances[msg.sender] = (balances[msg.sender]).sub(_value - burn_token);
    balances[_to] = (balances[_to]).add(_value - burn_token);
    emit Transfer(msg.sender, _to, _value - burn_token);
    require( burn(burn_token));
    return true;

}

function transferFrom(address _from, address _to, uint256 _value) public virtual override returns (bool) { require(_to != address(0) && _from != address(0) && _value > 0);

    uint burn_token = (_value*_brate)/100;
 require(_value+burn_token > _value);


    require(_value + burn_token <= balances[_from]);
 require(_value + burn_token <= allowed[_from][msg.sender]);
    
    balances[_from] = (balances[_from]).sub(_value - burn_token);
    balances[_to] = (balances[_to]).add(_value - burn_token);
    allowed[_from][msg.sender] = (allowed[_from][msg.sender]).sub( _value - burn_token);
    emit Transfer(_from, _to, _value - burn_token);
    require( burn(burn_token));
    return true;

}

function approve(address _spender, uint256 _value) public virtual override returns (bool) { allowed[msg.sender][_spender] = _value; emit Approval(msg.sender, _spender, _value); return true; }

function allowance(address _owner, address _spender) public view virtual override returns (uint256) { return allowed[_owner][_spender]; }

function burn(uint256 _value) public returns (bool success) { require(balances[msg.sender] >= _value); // Check if the sender has enough balances[msg.sender] -= _value; // Subtract from the sender _totalSupply -= _value; // Updates totalSupply emit Burn(msg.sender, _value); return true; }

/**
 * Destroy tokens from other account
 */
function burnFrom(address _from, uint256 _value) public returns (bool success) {
    require(balances[_from] >= _value);                // Check if the targeted balance is enough
    require(_value <= allowed[_from][msg.sender]);    // Check allowance
    balances[_from] -= _value;                         // Subtract from the targeted balance
    allowed[_from][msg.sender] -= _value;             // Subtract from the sender's allowance
    _totalSupply -= _value;                              // Update totalSupply
    emit Burn(_from, _value);
    return true;
}

//Admin can transfer his ownership to new address function transferownership(address _newaddress) public returns(bool){ require(msg.sender==_admin); _admin=_newaddress; return true; }

}