This is my personal note and might be some kind of user editorial/learning material for some people!
This is the sixth episode of this "note" series. I will write notes on problems (normally around 2400-ish problems), that are both interesting and educational. I normally will spend a few hours on each problem so please be patient when reading the blog.
If you want to motivate me to write a continuation (aka note 7), a significant upvote from you would be well appreciated! If I received lots of downvotes (because I'm also spending a lot of time to write this and to learn latex only to express my ideas accurately to you guys), I'm probably not gonna continuing writing these blogs.
Problem paraphrased：
Given a $$$N*M$$$ grid. Cell '.' denotes an empty cell, '#' denotes a wall and 'V' would the the starting position.
An exit is a cell with $$$.$$$ and is at the edge of the grid.
Type 1: grids with $$$V$$$ not able to visit any exits.
Type 2: grids with $$$V$$$ only able to visit exactly one exit.
Type 3: grids with $$$V$$$ able to visit $$$\geq 2$$$ exits
Find maximum replacement ('.' to '#') such that the type of grid remains the same.
Again , try the problem first before continuing.
Clearly we can seperate into 3 cases:
Phew, finally finished the problem~
The code looks slightly ugly, hope you guys can comprehend it.
Hope you guys learnt something from the blog. Thank you for reading.
