They gave me the same test on HackerRank which I did successfully (it passed all test cases). Yet my candidacy was rejected. I used a map container. I couldn't find any container suitable for the job. There may be a better solution which I am was not able to figure out. After reading this post, I am also feeling that they are biased :(

I'm curious about the "racially charged" - that's pretty bad. Since you mentioned 20 years it could be more a case of age discrimination (rampant in IT unfortunately) than racial bias.

The code was successfully written in HackerRank, which successfully compiled, passed 2/3 test cases and still they rejected candidate with Master Degree in Computer Engineering from US University and 20 years of proven record of writing the same code for many other Wall St. Clients.