APSAR (APSAR)

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

contract APSAR {
    string public name = "APSAR";
    string public symbol = "APSAR";
    uint8 public decimals = 18;
    uint256 public totalSupply;

    mapping(address => uint256) private balances;
    mapping(address => mapping(address => uint256)) private allowances;

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

    constructor() {
        // ???? Выпускаем 1 000 000 000 APSAR с 18 знаками
        totalSupply = 1_000_000_000 * 10 ** uint256(decimals);
        balances[msg.sender] = totalSupply;
        emit Transfer(address(0), msg.sender, totalSupply);
    }

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

    function transfer(address to, uint256 amount) public returns (bool) {
        require(to != address(0), "Transfer to zero address");
        require(balances[msg.sender] >= amount, "Insufficient balance");

        balances[msg.sender] -= amount;
        balances[to] += amount;

        emit Transfer(msg.sender, to, amount);
        return true;
    }

    function approve(address spender, uint256 amount) public returns (bool) {
        require(spender != address(0), "Approve to zero address");

        allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

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

    function transferFrom(address from, address to, uint256 amount) public returns (bool) {
        require(to != address(0), "Transfer to zero address");
        require(balances[from] >= amount, "Insufficient balance");
        require(allowances[from][msg.sender] >= amount, "Allowance exceeded");

        allowances[from][msg.sender] -= amount;
        balances[from] -= amount;
        balances[to] += amount;

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