文件 1 的 1：UniTopia.sol
pragma solidity 0.5.16;
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
require(c / a == b);
return c;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a / b;
return c;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
require(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
require(c >= a);
return c;
}
function ceil(uint256 a, uint256 m) internal pure returns (uint256) {
uint256 c = add(a,m);
uint256 d = sub(c,1);
return mul(div(d,m),m);
}
}
interface ApproveAndCallFallBack {
function receiveApproval(address from, uint256 tokens, address token, bytes calldata data) external;
}
contract owned {
address payable public owner;
address payable internal newOwner;
event OwnershipTransferred(address indexed _from, address indexed _to);
constructor() public {
owner = msg.sender;
emit OwnershipTransferred(address(0), owner);
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
function transferOwnership(address payable _newOwner) public onlyOwner {
newOwner = _newOwner;
}
function acceptOwnership() public {
require(msg.sender == newOwner);
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
newOwner = address(0);
}
}
contract UniTopia is owned {
using SafeMath for uint256;
bool public safeGuard=false;
string public constant name = "UniTopia";
string public constant symbol = "uTOPIA";
uint8 public constant decimals = 18;
uint256 public _totalSupply;
uint256 public tokenPrice;
uint256 public soldTokens;
uint256 public preMintedToken;
mapping(address=>uint256) public Pool;
mapping (address => uint256) private balances;
mapping (address => mapping (address => uint256)) private allowed;
event Transfer(address indexed from, address indexed to, uint256 value);
event TransferPoolamount(address _from, address _to, uint256 _ether);
event Approval(address _from, address _spender, uint256 _tokenAmt);
constructor(uint256 _supply,uint256 _price,uint256 _premint) public {
_totalSupply= _supply * (10 ** 18);
tokenPrice=_price;
soldTokens=_premint* (10 ** 18);
balances[msg.sender] = _premint* (10 ** 18);
emit Transfer(address(0), msg.sender, _premint* (10 ** 18));
}
function buyToken() payable public returns(bool)
{
require(msg.value!=0,"Invalid Amount");
uint256 one=10**18/tokenPrice;
uint256 tknAmount=one*msg.value;
require(soldTokens.add(tknAmount)<=_totalSupply,"Token Not Available");
balances[msg.sender]+=tknAmount;
Pool[owner]+=msg.value;
soldTokens+=tknAmount;
emit Transfer(address(this),msg.sender,tknAmount);
}
function withDraw() public onlyOwner{
require(Pool[owner]!=0,"No Ether Available");
owner.transfer(Pool[owner]);
emit TransferPoolamount(address(this),owner,Pool[owner]);
Pool[owner]=0;
}
function changeTokenPrice(uint256 _price) public onlyOwner{
require(_price!=0);
tokenPrice=_price;
}
function transfer(address to, uint256 value) public returns (bool) {
require(safeGuard==true,'Transfer Is Not Available');
require(value <= balances[msg.sender]);
require(to != address(0));
balances[msg.sender] = balances[msg.sender].sub(value);
balances[to] = balances[to].add(value);
emit Transfer(msg.sender, to, value);
return true;
}
function transferFrom(address from, address to, uint256 value) public returns (bool) {
require(safeGuard==true,'Transfer Is Not Available');
require(value <= balances[from]);
require(value <= allowed[from][msg.sender]);
require(to != address(0));
balances[from] = balances[from].sub(value);
balances[to] = balances[to].add(value);
allowed[from][msg.sender] = allowed[from][msg.sender].sub(value);
emit Transfer(from, to, value);
return true;
}
function multiTransfer(address[] memory receivers, uint256[] memory amounts) public {
uint256 arrayLength = receivers.length;
require(arrayLength <= 150, 'Too many addresses');
for (uint256 i = 0; i < arrayLength; i++) {
transfer(receivers[i], amounts[i]);
}
}
function approve(address spender, uint256 value) public returns (bool) {
require(spender != address(0));
allowed[msg.sender][spender] = value;
emit Approval(msg.sender, spender, value);
return true;
}
function approveAndCall(address spender, uint256 tokens, bytes calldata data) external returns (bool) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, address(this), data);
return true;
}
function increaseAllowance(address spender, uint256 addedValue) public returns (bool) {
require(spender != address(0));
allowed[msg.sender][spender] = allowed[msg.sender][spender].add(addedValue);
emit Approval(msg.sender, spender, allowed[msg.sender][spender]);
return true;
}
function decreaseAllowance(address spender, uint256 subtractedValue) public returns (bool) {
require(spender != address(0));
allowed[msg.sender][spender] = allowed[msg.sender][spender].sub(subtractedValue);
emit Approval(msg.sender, spender, allowed[msg.sender][spender]);
return true;
}
function burn(uint256 amount) external {
require(amount != 0);
require(amount <= balances[msg.sender]);
_totalSupply = _totalSupply.sub(amount);
balances[msg.sender] = balances[msg.sender].sub(amount);
emit Transfer(msg.sender, address(0), amount);
}
function changeSafeGuard() public onlyOwner{
safeGuard=true;
}
function tokenSold() public view returns(uint256)
{
return soldTokens;
}
function totalEther() public view returns(uint256)
{
return Pool[owner];
}
function availableToken() public view returns(uint256)
{
return _totalSupply.sub(soldTokens);
}
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
function balanceOf(address player) public view returns (uint256) {
return balances[player];
}
function allowance(address player, address spender) public view returns (uint256) {
return allowed[player][spender];
}
}
