Regent Coin - Audit

Users seem to be able to use `swaptransfer` to avoid transfer fee, which is pretty strange. Since it does not impose ant restriction on when and which user can use this, user could choose using `swaptransfer` instead of `transfer` forever, thus avoiding any potential fees, violating the tokenomics of the project.

Variable `_rOwned[account]` is not updated in the function `includeInReward()`, which will make the accounts included siphon off the tokens out of the balances of all token holders. The Rate was higher at the moment of the `excludeFromReward(account)` call, so the `_rOwned[account] / _tOwned[account]` ratio is bigger than expected for accounts included in the reward.

Performing integer division before multiplication truncates the low bits, losing the precision of calculation. ```solidity=681 uint256 unitBalance = deltaBalance / (denominator - temp.liquidity); ``` ```solidity=682 uint256 bnbToAddLiquidityWith = unitBalance * temp.liquidity; ```

The contract is serving as the underlying entity to interact with one or more third party protocols. The scope of the audit treats third party entities as black boxes and assume their functional correctness. However, in the real world, third parties can be compromised and this may lead to lost or stolen assets. In addition, upgrades of third parties can possibly create severe impacts, such as increasing fees of third parties, migrating to new LP pools, etc. ```solidity=142 IRouter public router; ``` - The contract `RegentCoin` interacts with third party contract with `IRouter` interface via `router`.