Notes

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

contract Lotto {
address public manager;
address payable[] public players;

constructor() {
manager = msg.sender;
}

function enter() public payable {
require(msg.value == 0.005 ether, "Incorrect ETH amount");
players.push(payable(msg.sender));
}

function getLotteryBalance() public view returns (uint) {
require(msg.sender == manager, "Not authorized");
return address(this).balance;
}

function getQuantityOfEntrants() public view returns (uint) {
return players.length;
}

function random() private view returns (uint) {
return uint(keccak256(abi.encodePacked(block.difficulty, block.timestamp, players.length)));
}

function selectWinner() public {
require(msg.sender == manager, "Not authorized");
require(players.length >= 3, "Not enough players");

uint index = random() % players.length;
players[index].transfer(address(this).balance);

// Reset the lottery for the next round
players = new address payable[](0);
}
}