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
  24. Lexicographic permutations
  25. 1000-digit Fibonacci number
  26. Reciprocal cycles
  27. Quadratic primes
  28. Number spiral diagonals
  29. Distinct powers
  30. Digit fifth powers
  31. Coin sums
  32. Pandigital products
  33. Digit cancelling fractions
  34. Digit factorials
  35. Circular primes
  36. Double-base palindromes
  37. Truncatable primes
  38. Pandigital multiples
  39. Integer right triangles
  40. Champernowne's constant
  41. Pandigital prime
  42. Coded triangle numbers
  43. Sub-string divisibility
  44. Pentagon numbers
  45. Triangular, pentagonal, and hexagonal
  1. Self powers
  1. Consecutive prime sum
  1. Lychrel numbers
  2. Powerful digit sum
  3. Square root convergents
  1. XOR decryption
  1. Maximum path sum II
  1. Totient maximum
  1. Path sum: two ways

CodeFights Solutions

Codingame Solutions

Easy ✓

Medium

Hard

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

Clash

Community

Hackerrank Solutions

Mathematics - Algebra

Mathematics - Fundamentals

Mathematics - Number Theory

Algorithms - Bit Manipulation

Algorithms - Implementation

SkillValue Solutions

Spotify Solutions

Misc Solutions