📦 the repo
 ┣📂 <problem's number>-<problem's name>  # The problem's identifier, e.g. 0001-two-sum
 ┃ ┣📜 PROBLEM.md                         # The problem description
 ┃ ┣📜 SOLUTIONS.md                       # The explanation for my solutions
 ┃ ┣📂 <solution 1>                       # The folder containing source code for the first solution, e.g. use-map
 ┃ ┃ ┣📜 <solution 1>.py                  # Python code for the solution (if any).
 ┃ ┃ ┗📜 <solution 1>.cpp                 # C++ code for the solution (if any).
 ┃ ┗📂 <more solutions ...>               # More solutions for the problem (if any).
 ┗📂 <more problems ...>                  # Other problems