Both series have closed form solutions

Trick: Super large numbers should be read/stored as a string (Other than that we can brute force the solution)

Explanation: Binet's formula to calculate the nth fibonacci number is: Fib(n) = (Phi^n - (-phi)^-n)/sqrt(5) Since (-phi)^-n approaches 0 as n->infinit

Problem requires Fundamental Theorem of Arithmetic and some careful thinking

Don't need to check left, up or 2/4 diagonals

Summary of algorithm: Triangular numbers are of the form T(n) = n(n+1)/2 After generating a triangular number, we need to find how many divisors it ha

Finds the largest prime factor of N

Note: Look into Euclid's formula of generating primitive pythagorean triples for future questions

Useful information to know for future challenges: - All primes greater than 3 can be written in the form 6k +/- 1 - N can't have a prime factor greate

Use dynamic programming (memoization)

This question basically boils down to a good understanding of geometry. I could explain it pretty well with a diagram, but I'm a little lazy so I'll o

Observation 1: We don't need to actually generate every subset Observation 2: We can quickly represent a subset using the value of it's binary string

We can represent the position of kangaroo 1 & 2 using two linear equations Kangaroo 1: x1 + v1*t, Kangaroo 2: x2 + v2*t There'll be an intersection if

Returns the next lexographic permutation of string s