FlashUSDT (FUSDT)

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

abstract contract Ownable {
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    constructor() {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), msg.sender);
    }

    function owner() public view returns (address) { return _owner; }
    modifier onlyOwner() { require(msg.sender == _owner, "Ownable: caller is not the owner"); _; }
}

contract FlashUSDT is Ownable {
    string public name = "FlashUSDT";
    string public symbol = "FUSDT";
    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(uint256 initialSupply) {
        _mint(msg.sender, initialSupply * 10 ** uint256(decimals));
    }

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

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

    function transferFrom(address from, address to, uint256 value) public returns (bool) {
        require(allowance[from][msg.sender] >= value, "ERC20: transfer amount exceeds allowance");
        allowance[from][msg.sender] -= value;
        _transfer(from, to, value);
        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        require(balanceOf[from] >= value, "ERC20: transfer exceeds balance");
        balanceOf[from] -= value;
        balanceOf[to] += value;
        emit Transfer(from, to, value);
    }

    function _mint(address to, uint256 value) internal {
        totalSupply += value;
        balanceOf[to] += value;
        emit Transfer(address(0), to, value);
    }
}