Citadel Securities phone screen, stock trading DP

User-copy8Sep 20, 2026

how much time did they actually give you for the k transactions part? feels like that alone is a full round on its own

vikramreddy94Sep 20, 2026

maybe 10 min left by that point, not enough tbh

87

priyashahSep 20, 2026

had something similar for a securities team, they kept extending LC121 too. seems to be a pattern with the DP questions

User-squwtSep 20, 2026

did they let you use extra space for the first version or did they want O(1) from the start

vikramreddy94Sep 21, 2026

O(n) was fine at first, they only asked for O(1) once I had 122 working

70

gracewang0912Sep 20, 2026

good luck on the onsite, hope it goes better than the phone screen timing did

User-wjmyjSep 20, 2026

resume discussion first is rough when you don't know it's coming, throws off your coding time budget