Dsa
Backtracking
Medium
The Artisan's Loom
An artisan is weaving a pattern using three colors of thread: Red (R), Lily (L), and Tulip (T). The weaver must use an exact count of each thread: R, L, and T. However, there are strict aesthetic rules: 1) No two Lily (L) threads can be adjacent. 2) No three threads of the same color can ever appear consecutively. Write a program to calculate the total number of unique valid sequences.
Input: Three space-separated integers R, L, and T representing the required count of each color.
Output: A single integer representing the number of valid sequences.
Example:
Input: 1 1 1
Output: 6
Explanation: All permutations (RLT, RTL, LTR, LRT, TRL, TLR) are valid because no Ls are adjacent and no three colors repeat.
Key concepts
backtrackingmemoizationcombinatorics
Practise this out loud — free
Start a mock interview on THIS exact question — a voice AI interviewer opens with it, pushes back like a real onsite, then hands you an instant scorecard.
🎙 Practise this question now