Practice · 2 of 3
Path Add via Four Points
CHALLENGE
Difficulty: advanced+25 XP
**Bài toán.** Rooted tree (root 1), initial zeros. q ops:
PA u v x adds x to every node on the path u..v; GET w prints value(w).
**Constraints:** 1 ≤ n, q ≤ 200 000; |x| ≤ 10^9. Four point updates +
one subtree-sum read per operation.
Press Submit to check your solution.
Back to lesson: Practice: Euler Query Trio