Why a Sudoku-solving program looks smart: Recursion, backtracking, and the idea of 'trying from the most likely failure points'

I was thinking about a program to solve Sudoku.You fill a 9x9 grid with numbers from 1 to 9. The same number must not be ...

Recursive functions are Turing-equivalent (Small tips to make middle and high school students like math 3)

A fact I recently learnedI recently finished reading a book on automata, and according to that book, Turing machines, lambda calculus, and recursive functions all have the same computational ...