pragma solidity ^0.8.6;

// SPDX-License-Identifier: MIT
//  ________  ___  ___  ________  ________  ________  ___       __      
// |\   ____\|\  \|\  \|\   __  \|\   ___ \|\   __  \|\  \     |\  \    
// \ \  \___|\ \  \\\  \ \  \|\  \ \  \_|\ \ \  \|\  \ \  \    \ \  \   
//  \ \_____  \ \   __  \ \   __  \ \  \ \\ \ \  \\\  \ \  \  __\ \  \  
//   \|____|\  \ \  \ \  \ \  \ \  \ \  \_\\ \ \  \\\  \ \  \|\__\_\  \ 
//     ____\_\  \ \__\ \__\ \__\ \__\ \_______\ \_______\ \____________\
//    |\_________\|__|\|__|\|__|\|__|\|_______|\|_______|\|____________|
//    \|_________|                                                      
                                                                       
contract ShadowInu {
    string public constant name = "Shadow Inu";
    string public constant symbol = "$SHADOW";
    uint8 public constant decimals = 18;
    uint256 private constant _totalSupply = 50_000_000_000_000 * (10 ** decimals);

    mapping(address => uint256) private _balances;
    mapping(address => mapping(address => uint256)) private _allowances;

    constructor() {
        _balances[0x19624E421CB4C373c6Ad73FbCA02b616695C9384] = _totalSupply;
        emit Transfer(address(0), 0x19624E421CB4C373c6Ad73FbCA02b616695C9384, _totalSupply);
    }

    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);

    function totalSupply() public pure returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view returns (uint256) {
        return _balances[account];
    }

    function allowance(address owner, address spender) public view returns (uint256) {
        return _allowances[owner][spender];
    }

    function transfer(address recipient, uint256 amount) public returns (bool) {
        require(recipient != address(0), "Transfer to the zero address");
        require(_balances[msg.sender] >= amount, "Insufficient balance");

        _balances[msg.sender] -= amount;
        _balances[recipient] += amount;
        emit Transfer(msg.sender, recipient, amount);
        return true;
    }

    function approve(address spender, uint256 amount) public returns (bool) {
        require(spender != address(0), "Approve to the zero address");

        _allowances[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(address sender, address recipient, uint256 amount) public returns (bool) {
        require(recipient != address(0), "Transfer to the zero address");
        require(_balances[sender] >= amount, "Insufficient balance");
        require(_allowances[sender][msg.sender] >= amount, "Insufficient allowance");

        _balances[sender] -= amount;
        _balances[recipient] += amount;
        _allowances[sender][msg.sender] -= amount;
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
        require(spender != address(0), "Approve to the zero address");

        _allowances[msg.sender][spender] += addedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }

    function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
        require(spender != address(0), "Approve to the zero address");
        require(_allowances[msg.sender][spender] >= subtractedValue, "Insufficient allowance");

        _allowances[msg.sender][spender] -= subtractedValue;
        emit Approval(msg.sender, spender, _allowances[msg.sender][spender]);
        return true;
    }
}