Encode Homework_4

VolcanoCoin.sol

// SPDX-License-Identifier: UNLICENSED 
pragma solidity ^0.8.7;

contract VolcanoCoin {
    uint public totalSupply = 10000;
    address owner;
    mapping(address => uint) public balances;
    error Unauthorized();
    
    constructor() {
        owner=msg.sender;
        balances[owner] = totalSupply;
    }
    
    modifier onlyOwner {
        if (msg.sender==owner) {
            _;
        }
    }
    
    struct Payments {
        uint transferAmount;
        address recipientAddr;
    }
    
    mapping (address => Payments) transactions;
    
    event TransferComplete(uint, address);
    
    function transfer(uint _amount, address _recipientAddr) public {
        if (msg.sender != owner) {
            revert Unauthorized();
        }
        payable(_recipientAddr).transfer(_amount);
        emit TransferComplete(_amount, _recipientAddr);
    }
    
    function getTotalSupply() public view returns(uint) {
        return totalSupply;
    }
    
    event TotalSupplyUpdated(uint);
    
    function increaseSupply(uint _totalSupply) public onlyOwner {
        _totalSupply = _totalSupply + 1000;
        emit TotalSupplyUpdated(_totalSupply);
    }
}