It strikes me as a surprise that I see a lot of super ugly pieces of code posted here which get thousands of upvotes.
The algorithm itself is often very neat but the translation into code is just horrible.

• variable names like "flag", "i or j" (for none loop counters), "map or list" (whats the reason to repeat the typename in the variable name??)
• formatting is completly inconsistent
• 2-3 condititions are put onto the same line only to make the solution shorter linewise
• a lot of duplicated code instead of extracting of variables or methods

I actually expected more from programmers which can solve medium-hard problems here.. I wouldn't hire a single one of them.

I encourage everyone which takes the time to posts code here to write it in an understandable way.