Those classes teach the algorithms and how to implement them. What they lack is: 1. how to recognize which algorithm the interviewer is expecting 2. how to pr

Those classes teach the algorithms and how to implement them. What they lack is: 1. how to recognize which algorithm the interviewer is expecting 2. how to present said algorithm on a whiteboard in under 30 min 3. how to speak fluently about the tradeoffs made in said whiteboard implementation 4. 'mutually agreed upon head compilation' where both you and the interviewer agree how your whiteboard code will be executed. These are skills that you can, and should, practice to interview with large companies. Leetcode helps with 1 and 2.