Gas in LimboDAO.seed(): Avoiding a 2N for-loop for a N one

[code423n4]

Handle

Dravee

Vulnerability details

Impact

Looping twice is expensive. It's possible to iterate only once from 0 to maxLength.

Proof of Concept

Original code iterating between N and 2N times here: https://github.com/code-423n4/2022-01-behodler/blob/71d8e0cfd9388f975d6a90dffba9b502b222bdfe/contracts/DAO/LimboDAO.sol#L195-L222

It's possible to iterate only N times on sushiLPs and uniLPs.
Here's the refacto I suggest, it starts from the comment //@audit refacto starts here and ends with //@audit refacto ends here:

File: LimboDAO.sol
213:     //@audit refacto starts here
214:     bool isSushiBigger = sushiLPs.length >= uniLPs.length;
215:     (uint256 shortLength, uint256 longLength) = isSushiBigger ? (uniLPs.length, sushiLPs.length) : (sushiLPs.length, uniLPs.length);
216: 
217:     for (uint256 i; i < shortLength; ++i) {
218:       sushiLoop(sushiLPs[i]);
219:       uniLoop(uniLPs[i]);
220:     }
221:     
222:     if (isSushiBigger) {
223:       for (uint256 i = shortLength; i < longLength; ++i) {
224:         sushiLoop(sushiLPs[i]);
225:       }
226:     } else {
227:       for (uint256 i = shortLength; i < longLength; ++i) {
228:         uniLoop(uniLPs[i]);
229:       }
230:     }
231:   }
232: 
233:   function sushiLoop(
234:     address sushiLp
235:   ) private {
236:     require(UniPairLike(sushiLp).factory() == sushiFactory, "LimboDAO: invalid Sushi LP");
237:     if (IERC20(eye).balanceOf(sushiLp) > 1000) assetApproved[sushiLp] = true;
238:     fateGrowthStrategy[sushiLp] = FateGrowthStrategy.indirectTwoRootEye;
239:   }
240: 
241:   function uniLoop(
242:     address uniLP
243:   ) private {
244:     require(UniPairLike(uniLP).factory() == uniFactory, "LimboDAO: invalid Uni LP"); //@audit-info Dravee: I corrected the comment
245:     if (IERC20(eye).balanceOf(uniLP) > 1000) assetApproved[uniLP] = true;
246:     fateGrowthStrategy[uniLP] = FateGrowthStrategy.indirectTwoRootEye;
247:   }
248:   //@audit refacto ends here

Tools Used

VS Code

Recommended Mitigation Steps

Apply the suggested refacto