路径个数问题

矩阵中和能被 K 整除的路径
https://leetcode.cn/problems/paths-in-matrix-whose-sum-is-divisible-by-k/description/

最小体力消耗路径(生成树，不是dp)
https://leetcode.cn/problems/path-with-minimum-effort/description/

地下城游戏 （ 倒推）
https://leetcode.cn/problems/dungeon-game/description/