Puzzles are a very ... interesting entertainment.
I made them when I was bored and curious about my puzzles abilities.
The algorithm I used is backtracing with additional techniques in each solver.
They're not perfect, but pretty good at easy and medium puzzles, and decent at hard ones (mainly tested on Logi puzzles). In the future, after learning about new algorithms and optimization techniques, I'm planning to refresh them all by optimizing and add new ones :].