1. two sum
2. add two numbers -- faster than 100%
3. longest substring -- faster than 70.20%
4. Median of Two Sorted Arrays
5. Reverse Integer -- faster than 100%
6. best-time-to-buy-and-sell-stock -- faster than 94%
7. best-time-to-buy-and-sell-stock-ii -- faster than 100%
8. best-time-to-buy-and-sell-stock-iii -- TODO
9. N-Repeated Element in Size 2N Array -- pass

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