Contract Source Code:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.30;

contract PangDongLai {
    string public constant name = "PDL Token";
    string public constant symbol = "DL";
    uint8  public constant decimals = 18;

    uint256 public totalSupply;
    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(address receiver) {
        totalSupply = 10_000_000_000 * (10 ** uint256(decimals));
        balanceOf[receiver] = totalSupply;
        emit Transfer(address(0), receiver, totalSupply);
    }

    function transfer(address to, uint256 amount) external returns (bool) {
        _transfer(msg.sender, to, amount);
        return true;
    }

    function approve(address spender, uint256 amount) external returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }
    

    function transferFrom(address from, address to, uint256 amount) external returns (bool) {
        uint256 cur = allowance[from][msg.sender];
        require(cur >= amount, "ALLOWANCE_EXCEEDED");
        if (cur != type(uint256).max) {
            unchecked { allowance[from][msg.sender] = cur - amount; }
            emit Approval(from, msg.sender, allowance[from][msg.sender]);
        }
        _transfer(from, to, amount);
        return true;
    }

    function _transfer(address from, address to, uint256 amount) internal {
        require(from != address(0), "FROM_IS_ZERO");
        require(to != address(0), "TO_IS_ZERO");

        uint256 bal = balanceOf[from];
        require(bal >= amount, "BALANCE_TOO_LOW");

        unchecked { balanceOf[from] = bal - amount; }
        balanceOf[to] += amount;

        emit Transfer(from, to, amount);
    }
}