It is my 30 minutes study of Leetcode contest leader board top 150. I did have some experience on Hackerrank contest leader board. The link is here, global ranking.
I think that it is so important for me to understand how good they are. Compared to those players, I have a lot of work to do to catch up.
I read one of players's github in top 250, he finished over 500 algorithm in 45 days. I just could not believe that.