Y2k Finance contest - ignacio's results

1 Use != 0 instead of > 0 at the above mentioned codes. The variable is uint, so it will not be below 0 so it can just check != 0.

!= 0 costs less gas compared to > 0 for unsigned integers in require statements with the optimizer enabled https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/StakingRewards.sol#L134

2 MULTIPLE ADDRESS MAPPINGS CAN BE COMBINED INTO A SINGLE MAPPING OF AN ADDRESS TO A STRUCT, WHERE APPROPRIATE

Saves a storage slot for the mapping. Depending on the circumstances and sizes of types, can avoid a Gsset (20000 gas) per mapping combined. Reads and subsequent writes can also be cheaper when a function requires both values and they both fit in the same storage slot https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L47

3 ( ++I/I++ ) SHOULD BE UNCHECKED{++I}/UNCHECKED{I++} WHEN IT IS NOT POSSIBLE FOR THEM TO OVERFLOW, AS IS THE CASE WHEN USED IN FOR- AND WHILE-LOOPS

++I COSTS LESS GAS THAN I++ The unchecked keyword is new in solidity version 0.8.0, so this only applies to that version or higher, which these instances are. This saves 30-40 gas per loop For example for (uint i; i < length; ) { // do stuff unchecked { ++i; } } https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/Vault.sol#L443

4 ABI.ENCODE() IS LESS EFFICIENT THAN ABI.ENCODEPACKED()

https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/RewardsFactory.sol#L118 https://github.com/code-423n4/2022-09-y2k-finance/blob/main/src/rewards/RewardsFactory.sol#L150