leetcode-710 - Random Pick with Blacklist
動機 random題都很奇妙 ...
Randomized
leetcode-398 - Random Pick Index
動機 要找時間看Reservoir Sampling ...
leetcode-470 - Implement Rand10() Using Rand7()
動機 這三小 ...
leetcode-384 - Shuffle an Array
動機 python有shuffle ...
leetcode-380 - Insert Delete GetRandom O(1)
動機 真的就是用rand!! ...