Citadel Financial Technology Associate interview questions

On Campus Interview, several probability questions, several C++ questions , several algorithm questions, in an hour. Lots of questions, need to move fast. You really need to know a lot about C++ and algorithm.

First had an on-campus interview, 2 rounds, 45min each. Asked about OOD, Fibonacci with DP. Invited to Chicago for onsite, 4 rounds, 45min each. Questions like 1.how does hashmap work, 2.how many ways are there to go from top left of chess board to bottom right. 3.How to sort 1 trillion bits of data. 4.operator= override in c++ 5. 50 white balls, 50 black balls, 2 jars. How to put balls into jars to maximize the probability of getting white ball when blindly get a ball from a random jar.