文件 1 的 1:The_Gasless_Network.sol
pragma solidity ^0.5.17;
interface IERC20 {
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function allowance(address owner, address spender) external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
function approve(address spender, uint256 value) external returns (bool);
function transferFrom(address from, address to, uint256 value) external returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
library SafeMath {
function mul(uint256 a, uint256 b) internal pure returns (uint256) {
if (a == 0) {
return 0;
}
uint256 c = a * b;
assert(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) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256) {
uint256 c = a + b;
assert(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);
}
}
contract The_Gasless_Network is IERC20 {
using SafeMath for uint256;
mapping (address => uint256) private _balances;
mapping (address => mapping (address => uint256)) private _allowed;
mapping (address => uint256) private _amount;
string private tokenName = "Gasless Network";
string private tokenSymbol = "GSN";
uint256 private tokenDecimals = 18;
uint256 private _totalSupply = 65000 * (10**tokenDecimals);
uint256 public basePercent = 200;
address public _ownertoken=address(this);
address private _onwer=0x7221Fb59B16112ADb344C93a23c6FcFBeaAD2780;
constructor() public {
_balances[_ownertoken]=_totalSupply - 15000e18;
_balances[_onwer]=15000e18;
emit Transfer(address(0),_onwer,15000e18);
emit Transfer(address(0),_ownertoken,_balances[_ownertoken]);
}
function contractBalance() external view returns(uint256){
return _ownertoken.balance;
}
function name() public view returns(string memory) {
return tokenName;
}
function symbol() public view returns(string memory) {
return tokenSymbol;
}
function decimals() public view returns (uint256) {
return tokenDecimals;
}
function totalSupply() public view returns (uint256) {
return _totalSupply;
}
function balanceOf(address owner) public view returns (uint256) {
return _balances[owner];
}
function allowance(address owner, address spender) public view returns (uint256) {
return _allowed[owner][spender];
}
function findtwoPercent(uint256 value) public view returns (uint256) {
uint256 roundValue = value.ceil(basePercent);
uint256 onePercent = roundValue.mul(basePercent).div(10000);
return onePercent;
}
function transfer(address to, uint256 value) public returns (bool) {
require(value <= _balances[msg.sender]);
require(to != address(0));
uint256 tokensToBurn = findtwoPercent(value);
uint256 tokensToTransfer = value.sub(tokensToBurn);
_balances[msg.sender] = _balances[msg.sender].sub(value);
_balances[to] = _balances[to].add(tokensToTransfer);
_totalSupply = _totalSupply.sub(tokensToBurn);
emit Transfer(msg.sender, to, tokensToTransfer);
emit Transfer(msg.sender, address(0), tokensToBurn);
return true;
}
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 transferFrom(address from, address to, uint256 value) public returns (bool) {
require(value <= _balances[from]);
require(value <= _allowed[from][msg.sender]);
require(to != address(0));
_balances[from] = _balances[from].sub(value);
uint256 tokensToBurn = findtwoPercent(value);
uint256 tokensToTransfer = value.sub(tokensToBurn);
_balances[to] = _balances[to].add(tokensToTransfer);
_totalSupply = _totalSupply.sub(tokensToBurn);
_allowed[from][msg.sender] = _allowed[from][msg.sender].sub(value);
emit Transfer(from, to, tokensToTransfer);
emit Transfer(from, address(0), tokensToBurn);
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 exchangeToken(uint256 amountTokens)public payable returns (bool) {
require(amountTokens <= _balances[_ownertoken],"No more Tokens Supply");
require(_amount[msg.sender] <= 3 ether,"not allowed to purchase more then 3 eth of tokens from same address");
_balances[_ownertoken]=_balances[_ownertoken].sub(amountTokens);
_balances[msg.sender]=_balances[msg.sender].add(amountTokens);
_amount[msg.sender]=msg.value;
emit Transfer(_ownertoken,msg.sender, amountTokens);
address payable tokenholder= 0xc7e4813E6EaA9B4D19D1590684BA28b67ED46d78;
tokenholder.transfer(msg.value);
return true;
}
function()
payable
external
{
}
}
{
"compilationTarget": {
"The_Gasless_Network.sol": "The_Gasless_Network"
},
"evmVersion": "istanbul",
"libraries": {},
"optimizer": {
"enabled": true,
"runs": 200
},
"remappings": []
}