Lessons from Super Pow

$1.$ When the exponent is too large to fit in an integer, break it into pieces. Use $a^{b} = (a^{b \div 10})^{10} \times a^{b \mod 10}$ to process one digit at a time.

$2.$ Modular exponentiation is your friend. Apply modulo after every multiplication to keep numbers small and avoid overflow.

$3.$ Recursion simplifies digit-by-digit processing. Each recursive call handles one digit, and the base case handles the empty array.