Leetcode DP & other mostly medium & hard problems

Solutions for https://leetcode.com/tag/dynamic-programming/ in JAVA..., my profile is accessible at https://leetcode.com/jargnar/ with acceptance rate ~41% as of Jan 2020 because I used the submit button as a proxy debugger in much of 2018-19... one can only get wiser as time passes. Most of the DP problems are quite hard and take many days of thinking, some times I cheat by going on YouTube -- these days, there are a lot of enthusiastic people on YouTube walking through Leetcode problems. Life is good, I suppose.