Robert Eisele
Engineer, Systems Architect and DBA

Programming Puzzle Solutions

Competitive programming is a good way to learn very rapidly, since problems are stated which are not that common in day-to-day business needs, but it's a personal and intellectual challenge. It's my sudoku if you will. In order to keep track, I decided to post the solutions to challenges I participated to, not to be a spoiler but to give motivation to find better solutions to these interesting problems.

Project Euler Solutions

  1. Multiples of 3 and 5
  2. Even Fibonacci numbers
  3. Largest prime factor
  4. Largest palindrome product
  5. Smallest multiple
  6. Sum square difference
  7. 10001st prime
  8. Largest product in a series
  9. Special Pythagorean triplet
  10. Summation of primes
  11. Largest product in a grid
  12. Highly divisible triangular number
  13. Large sum
  14. Longest Collatz sequence
  15. Lattice paths
  16. Power digit sum
  17. Number letter counts
  18. Maximum path sum I
  19. Counting Sundays
  20. Factorial digit sum
  21. Amicable numbers
  22. Names scores
  23. Non-abundant sums
  1. 1000-digit Fibonacci number
  1. Quadratic primes
  2. Number spiral diagonals
  1. Digit fifth powers
  1. Digit cancelling fractions
  2. Digit factorials
  3. Circular primes
  4. Double-base palindromes
  1. Pentagon numbers
  1. Maximum path sum II
  1. Path sum: two ways

CodeFights Solutions

Codingame Solutions

Easy ✓



Very Hard

  • Music Scores
  • Mars Lander - Episode 3
  • The Resistance
  • Shadows of the Knight - Episode 2
  • Nintendo Sponsored Contest
  • The Last Crusade - Episode 3
  • Vox Codei - Episode 2



Hackerrank Solutions

Mathematics - Algebra

Mathematics - Fundamentals

Mathematics - Number Theory

Algorithms - Bit Manipulation

Algorithms - Implementation

SkillValue Solutions

Spotify Solutions

Misc Solutions