/*********************
     * www.publicoin.info *
     **********************/

// File: @openzeppelin/contracts/utils/Context.sol
 
 
// OpenZeppelin Contracts v4.4.1 (utils/Context.sol)
 
pragma solidity ^0.8.0;
 
/**
* @dev Provides information about the current execution context, including the
* sender of the transaction and its data. While these are generally available
* via msg.sender and msg.data, they should not be accessed in such a direct
* manner, since when dealing with meta-transactions the account sending and
* paying for execution may not be the actual sender (as far as an application
* is concerned).
*
* This contract is only required for intermediate, library-like contracts.
*/
abstract contract Context {
   function _msgSender() internal view virtual returns (address) {
       return msg.sender;
   }
 
   function _msgData() internal view virtual returns (bytes calldata) {
       return msg.data;
   }
}
 
// File: @openzeppelin/contracts/token/ERC20/IERC20.sol
 
 
// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)
 
pragma solidity ^0.8.0;
 
/**
* @dev Interface of the ERC20 standard as defined in the EIP.
*/
interface IERC20 {
   /**
    * @dev Emitted when `value` tokens are moved from one account (`from`) to
    * another (`to`).
    *
    * Note that `value` may be zero.
    */
   event Transfer(address indexed from, address indexed to, uint256 value);
 
   /**
    * @dev Emitted when the allowance of a `spender` for an `owner` is set by
    * a call to {approve}. `value` is the new allowance.
    */
   event Approval(address indexed owner, address indexed spender, uint256 value);
 
   /**
    * @dev Returns the amount of tokens in existence.
    */
   function totalSupply() external view returns (uint256);
 
   /**
    * @dev Returns the amount of tokens owned by `account`.
    */
   function balanceOf(address account) external view returns (uint256);
 
   /**
    * @dev Moves `amount` tokens from the caller's account to `to`.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * Emits a {Transfer} event.
    */
   function transfer(address to, uint256 amount) external returns (bool);
 
   /**
    * @dev Returns the remaining number of tokens that `spender` will be
    * allowed to spend on behalf of `owner` through {transferFrom}. This is
    * zero by default.
    *
    * This value changes when {approve} or {transferFrom} are called.
    */
   function allowance(address owner, address spender) external view returns (uint256);
 
   /**
    * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * IMPORTANT: 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
    *
    * Emits an {Approval} event.
    */
   function approve(address spender, uint256 amount) external returns (bool);
 
   /**
    * @dev Moves `amount` tokens from `from` to `to` using the
    * allowance mechanism. `amount` is then deducted from the caller's
    * allowance.
    *
    * Returns a boolean value indicating whether the operation succeeded.
    *
    * Emits a {Transfer} event.
    */
   function transferFrom(
       address from,
       address to,
       uint256 amount
   ) external returns (bool);
}
 
// File: @openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol
 
 
// OpenZeppelin Contracts v4.4.1 (token/ERC20/extensions/IERC20Metadata.sol)
 
pragma solidity ^0.8.0;
 
 
/**
* @dev Interface for the optional metadata functions from the ERC20 standard.
*
* _Available since v4.1._
*/
interface IERC20Metadata is IERC20 {
   /**
    * @dev Returns the name of the token.
    */
   function name() external view returns (string memory);
 
   /**
    * @dev Returns the symbol of the token.
    */
   function symbol() external view returns (string memory);
 
   /**
    * @dev Returns the decimals places of the token.
    */
   function decimals() external view returns (uint8);
}
 
// File: @openzeppelin/contracts/token/ERC20/ERC20.sol
 
 
// OpenZeppelin Contracts (last updated v4.7.0) (token/ERC20/ERC20.sol)
 
pragma solidity ^0.8.0;
 
 
 
 
/**
* @dev Implementation of the {IERC20} interface.
*
* This implementation is agnostic to the way tokens are created. This means
* that a supply mechanism has to be added in a derived contract using {_mint}.
* For a generic mechanism see {ERC20PresetMinterPauser}.
*
* TIP: For a detailed writeup see our guide
* https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
* to implement supply mechanisms].
*
* We have followed general OpenZeppelin Contracts guidelines: functions revert
* instead returning `false` on failure. This behavior is nonetheless
* conventional and does not conflict with the expectations of ERC20
* applications.
*
* Additionally, an {Approval} event is emitted on calls to {transferFrom}.
* This allows applications to reconstruct the allowance for all accounts just
* by listening to said events. Other implementations of the EIP may not emit
* these events, as it isn't required by the specification.
*
* Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
* functions have been added to mitigate the well-known issues around setting
* allowances. See {IERC20-approve}.
*/
contract ERC20 is Context, IERC20, IERC20Metadata {
   mapping(address => uint256) private _balances;
 
   mapping(address => mapping(address => uint256)) private _allowances;
 
   uint256 private _totalSupply;
 
   string private _name;
   string private _symbol;
 
   /**
    * @dev Sets the values for {name} and {symbol}.
    *
    * The default value of {decimals} is 18. To select a different value for
    * {decimals} you should overload it.
    *
    * All two of these values are immutable: they can only be set once during
    * construction.
    */
   constructor(string memory name_, string memory symbol_) {
       _name = name_;
       _symbol = symbol_;
   }
 
   /**
    * @dev Returns the name of the token.
    */
   function name() public view virtual override returns (string memory) {
       return _name;
   }
 
   /**
    * @dev Returns the symbol of the token, usually a shorter version of the
    * name.
    */
   function symbol() public view virtual override returns (string memory) {
       return _symbol;
   }
 
   /**
    * @dev Returns the number of decimals used to get its user representation.
    * For example, if `decimals` equals `2`, a balance of `505` tokens should
    * be displayed to a user as `5.05` (`505 / 10 ** 2`).
    *
    * Tokens usually opt for a value of 18, imitating the relationship between
    * Ether and Wei. This is the value {ERC20} uses, unless this function is
    * overridden;
    *
    * NOTE: This information is only used for _display_ purposes: it in
    * no way affects any of the arithmetic of the contract, including
    * {IERC20-balanceOf} and {IERC20-transfer}.
    */
   function decimals() public view virtual override returns (uint8) {
       return 18;
   }
 
   /**
    * @dev See {IERC20-totalSupply}.
    */
   function totalSupply() public view virtual override returns (uint256) {
       return _totalSupply;
   }
 
   /**
    * @dev See {IERC20-balanceOf}.
    */
   function balanceOf(address account) public view virtual override returns (uint256) {
       return _balances[account];
   }
 
   /**
    * @dev See {IERC20-transfer}.
    *
    * Requirements:
    *
    * - `to` cannot be the zero address.
    * - the caller must have a balance of at least `amount`.
    */
   function transfer(address to, uint256 amount) public virtual override returns (bool) {
       address owner = _msgSender();
       _transfer(owner, to, amount);
       return true;
   }
 
   /**
    * @dev See {IERC20-allowance}.
    */
   function allowance(address owner, address spender) public view virtual override returns (uint256) {
       return _allowances[owner][spender];
   }
 
   /**
    * @dev See {IERC20-approve}.
    *
    * NOTE: If `amount` is the maximum `uint256`, the allowance is not updated on
    * `transferFrom`. This is semantically equivalent to an infinite approval.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    */
   function approve(address spender, uint256 amount) public virtual override returns (bool) {
       address owner = _msgSender();
       _approve(owner, spender, amount);
       return true;
   }
 
   /**
    * @dev See {IERC20-transferFrom}.
    *
    * Emits an {Approval} event indicating the updated allowance. This is not
    * required by the EIP. See the note at the beginning of {ERC20}.
    *
    * NOTE: Does not update the allowance if the current allowance
    * is the maximum `uint256`.
    *
    * Requirements:
    *
    * - `from` and `to` cannot be the zero address.
    * - `from` must have a balance of at least `amount`.
    * - the caller must have allowance for ``from``'s tokens of at least
    * `amount`.
    */
   function transferFrom(
       address from,
       address to,
       uint256 amount
   ) public virtual override returns (bool) {
       address spender = _msgSender();
       _spendAllowance(from, spender, amount);
       _transfer(from, to, amount);
       return true;
   }
 
   /**
    * @dev Atomically increases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {IERC20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    */
   function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
       address owner = _msgSender();
       _approve(owner, spender, allowance(owner, spender) + addedValue);
       return true;
   }
 
   /**
    * @dev Atomically decreases the allowance granted to `spender` by the caller.
    *
    * This is an alternative to {approve} that can be used as a mitigation for
    * problems described in {IERC20-approve}.
    *
    * Emits an {Approval} event indicating the updated allowance.
    *
    * Requirements:
    *
    * - `spender` cannot be the zero address.
    * - `spender` must have allowance for the caller of at least
    * `subtractedValue`.
    */
   function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
       address owner = _msgSender();
       uint256 currentAllowance = allowance(owner, spender);
       require(currentAllowance >= subtractedValue, "ERC20: decreased allowance below zero");
       unchecked {
           _approve(owner, spender, currentAllowance - subtractedValue);
       }
 
       return true;
   }
 
   /**
    * @dev Moves `amount` of tokens from `from` to `to`.
    *
    * This internal function is equivalent to {transfer}, and can be used to
    * e.g. implement automatic token fees, slashing mechanisms, etc.
    *
    * Emits a {Transfer} event.
    *
    * Requirements:
    *
    * - `from` cannot be the zero address.
    * - `to` cannot be the zero address.
    * - `from` must have a balance of at least `amount`.
    */
   function _transfer(
       address from,
       address to,
       uint256 amount
   ) internal virtual {
       require(from != address(0), "ERC20: transfer from the zero address");
       require(to != address(0), "ERC20: transfer to the zero address");
 
       _beforeTokenTransfer(from, to, amount);
 
       uint256 fromBalance = _balances[from];
       require(fromBalance >= amount, "ERC20: transfer amount exceeds balance");
       unchecked {
           _balances[from] = fromBalance - amount;
       }
       _balances[to] += amount;
 
       emit Transfer(from, to, amount);
 
       _afterTokenTransfer(from, to, amount);
   }
 
   /** @dev Creates `amount` tokens and assigns them to `account`, increasing
    * the total supply.
    *
    * Emits a {Transfer} event with `from` set to the zero address.
    *
    * Requirements:
    *
    * - `account` cannot be the zero address.
    */
   function _mint(address account, uint256 amount) internal virtual {
       require(account != address(0), "ERC20: mint to the zero address");
 
       _beforeTokenTransfer(address(0), account, amount);
 
       _totalSupply += amount;
       _balances[account] += amount;
       emit Transfer(address(0), account, amount);
 
       _afterTokenTransfer(address(0), account, amount);
   }
 
   /**
    * @dev Destroys `amount` tokens from `account`, reducing the
    * total supply.
    *
    * Emits a {Transfer} event with `to` set to the zero address.
    *
    * Requirements:
    *
    * - `account` cannot be the zero address.
    * - `account` must have at least `amount` tokens.
    */
   function _burn(address account, uint256 amount) internal virtual {
       require(account != address(0), "ERC20: burn from the zero address");
 
       _beforeTokenTransfer(account, address(0), amount);
 
       uint256 accountBalance = _balances[account];
       require(accountBalance >= amount, "ERC20: burn amount exceeds balance");
       unchecked {
           _balances[account] = accountBalance - amount;
       }
       _totalSupply -= amount;
 
       emit Transfer(account, address(0), amount);
 
       _afterTokenTransfer(account, address(0), amount);
   }
 
   /**
    * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
    *
    * This internal function is equivalent to `approve`, and can be used to
    * e.g. set automatic allowances for certain subsystems, etc.
    *
    * Emits an {Approval} event.
    *
    * Requirements:
    *
    * - `owner` cannot be the zero address.
    * - `spender` cannot be the zero address.
    */
   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);
   }
 
   /**
    * @dev Updates `owner` s allowance for `spender` based on spent `amount`.
    *
    * Does not update the allowance amount in case of infinite allowance.
    * Revert if not enough allowance is available.
    *
    * Might emit an {Approval} event.
    */
   function _spendAllowance(
       address owner,
       address spender,
       uint256 amount
   ) internal virtual {
       uint256 currentAllowance = allowance(owner, spender);
       if (currentAllowance != type(uint256).max) {
           require(currentAllowance >= amount, "ERC20: insufficient allowance");
           unchecked {
               _approve(owner, spender, currentAllowance - amount);
           }
       }
   }
 
   /**
    * @dev Hook that is called before any transfer of tokens. This includes
    * minting and burning.
    *
    * Calling conditions:
    *
    * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
    * will be transferred to `to`.
    * - when `from` is zero, `amount` tokens will be minted for `to`.
    * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
    * - `from` and `to` are never both zero.
    *
    * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
    */
   function _beforeTokenTransfer(
       address from,
       address to,
       uint256 amount
   ) internal virtual {}
 
   /**
    * @dev Hook that is called after any transfer of tokens. This includes
    * minting and burning.
    *
    * Calling conditions:
    *
    * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
    * has been transferred to `to`.
    * - when `from` is zero, `amount` tokens have been minted for `to`.
    * - when `to` is zero, `amount` of ``from``'s tokens have been burned.
    * - `from` and `to` are never both zero.
    *
    * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
    */
   function _afterTokenTransfer(
       address from,
       address to,
       uint256 amount
   ) internal virtual {}
}
 
// File: publicoin.sol
 
 
 
pragma solidity 0.8.16;
 
 
contract Proof_of_transaction is ERC20 {
   mapping(uint => uint) public _startsubsidy;
   mapping(uint => uint) public _endsubsidy;
   mapping(uint => uint) public _subsidy;
 
   constructor() ERC20("Publicoin", "Pcoin") {
       _mint(address(this), 21000000000000000000000000);
      
       _startsubsidy[1] = 21000000000000000000000000;   
       _endsubsidy[1] = 20000100000000000000000000;       
       _subsidy[1] = 100000000000000000000;          
 
       _startsubsidy[2] = 20000100000000000000000000;    
       _endsubsidy[2] = 19000050000000000000000000;      
       _subsidy[2] = 50000000000000000000;           
 
       _startsubsidy[3] = 19000050000000000000000000;    
       _endsubsidy[3] = 18000025000000000000000000;     
       _subsidy[3] = 25000000000000000000;          
 
       _startsubsidy[4] = 18000025000000000000000000;     
       _endsubsidy[4] = 17000012500000000000000000;     
       _subsidy[4] = 12500000000000000000;          
 
       _startsubsidy[5] = 17000012500000000000000000;   
       _endsubsidy[5] = 16000006250000000000000000;
       _subsidy[5] = 6250000000000000000;          
 
       _startsubsidy[6] = 16000006250000000000000000;    
       _endsubsidy[6] = 15000003125000000000000000;      
       _subsidy[6] = 3125000000000000000;           
 
       _startsubsidy[7] = 15000003125000000000000000;   
       _endsubsidy[7] = 14000001562500000000000000;     
       _subsidy[7] = 1562500000000000000;          
 
       _startsubsidy[8] = 14000001562500000000000000;   
       _endsubsidy[8] = 13000000781250000000000000;     
       _subsidy[8] = 781250000000000000;          
 
       _startsubsidy[9] = 13000000781250000000000000;   
       _endsubsidy[9] = 12000000390625000000000000;      
       _subsidy[9] =  390625000000000000;          
 
       _startsubsidy[10] = 12000000390625000000000000;    
       _endsubsidy[10] =  11000000195312500000000000;      
       _subsidy[10] = 195312500000000000;           
 
       _startsubsidy[11] = 11000000195312500000000000;   
       _endsubsidy[11] = 10000000097656250000000000;     
       _subsidy[11] =  97656250000000000;          
 
       _startsubsidy[12] = 10000000097656250000000000;     
       _endsubsidy[12] = 9000000048828125000000000;    
       _subsidy[12] = 48828125000000000;  

       _startsubsidy[13] = 9000000048828125000000000;   
       _endsubsidy[13] = 8000000024414062500000000;     
       _subsidy[13] = 24414062500000000;          
 
       _startsubsidy[14] = 8000000024414062500000000;    
       _endsubsidy[14] = 7000000012207031250000000;      
       _subsidy[14] = 12207031250000000;          
 
       _startsubsidy[15] = 7000000012207031250000000;    
       _endsubsidy[15] = 6000000006103515625000000;     
       _subsidy[15] = 6103515625000000;          
 
       _startsubsidy[16] = 6000000006103515625000000;    
       _endsubsidy[16] = 5000000003051757812500000;     
       _subsidy[16] = 3051757812500000; 

       _startsubsidy[17] = 5000000003051757812500000;     
       _endsubsidy[17] = 4000000001525878906250000;    
       _subsidy[17] = 1525878906250000; 

       _startsubsidy[18] = 4000000001525878906250000;   
       _endsubsidy[18] = 3000000000762939453125000;     
       _subsidy[18] = 762939453125000;          
 
       _startsubsidy[19] = 3000000000762939453125000;    
       _endsubsidy[19] = 2000000000381469726562500;      
       _subsidy[19] = 381469726562500;          
 
       _startsubsidy[20] = 2000000000381469726562500;    
       _endsubsidy[20] = 1000000000190734863281250;     
       _subsidy[20] = 190734863281250;          
 
       _startsubsidy[21] = 1000000000190734863281250;    
       _endsubsidy[21] = 95367431640624;     
       _subsidy[21] = 95367431640625;          
 
       _startsubsidy[0] = 95367431640624;    
       _endsubsidy[0] = 0;     
       _subsidy[0] = 0;
 
   }
 
   function transfer(address recipient, uint256 amount) public override returns (bool) {
          _transferWithsubsidy(msg.sender, recipient, amount);
       return true;
   }
 
 
   function transferFrom(
       address sender,
       address recipient,
       uint256 amount
   ) public override returns (bool) {
       _transferWithsubsidy(sender, recipient, amount);
       return true;
   }
 
   function _transferWithsubsidy( address sender, address recipient, uint amount ) internal {
       _transfer(sender, recipient, amount);
        if(msg.sender == tx.origin) {
         _distributesubsidy();
       }
   }
 
 
   function _distributesubsidy() internal {
       for(uint i = 0; i <= 21; i++){
           if (
               _startsubsidy[i] >= super.balanceOf(address(this))  &&
               _endsubsidy[i] <= super.balanceOf(address(this))
           ) {
               _transfer(address(this), msg.sender, _subsidy[i]);
               return;
           }
       }
   }
 
   receive() external payable {
       revert();
   }
}