Leetcode 3320. Count The Number of Winning Sequences

Given Alice's fixed length-n sequence of moves in a rock-paper-scissors cycle (F beats E, W beats F, E beats W), count how many length-n sequences Bob can play (never repeating the same creature in consecutive rounds) that give Bob a strictly higher total score than Alice, modulo 1e9+7. The core challenge is counting constrained sequences, typically solved by dynamic programming that tracks the round index, Bob's last move, and the running score difference.