Answers of type-challenges, I have added comments to some questions that I think are quite challenging.
00012-medium-chainable-options
01367-medium-remove-index-signature
01978-medium-percentage-parser
03188-medium-tuple-to-nested-object
04182-medium-fibonacci-sequence
09142-medium-checkrepeatedchars
09286-medium-firstuniquecharindex
09896-medium-get-middle-element
09898-medium-zhao-chu-mu-biao-shu-zu-zhong-zhi-chu-xian-guo-yi-ci-de-yuan-su