• 오일러 경로 테크닉을 적용한 뒤, 구간합 업데이트 + 포인트 쿼리를 처리하는 문제.
• 서브트리의 루트도 업데이트 된다는 점만 제외하면 자동차 공장과 동일한 문제이므로, 자세한 풀이는 그쪽을 참조.
• 주식회사 승범이네와는 문제가 전부 똑같다.

"""Solution code for "BOJ 14268. 회사 문화 2".

- Problem link: https://www.acmicpc.net/problem/14268
- Solution link: http://www.teferi.net/ps/problems/boj/14268
"""

import sys
from teflib import fenwicktree
from teflib import tgraph


def euler_tour_technique(tree, root):
    subtree_ranges = [[None, None] for _ in tree]
    order = 0
    for node in tgraph.dfs(tree, root, yields_on_leave=True):
        if subtree_ranges[node][0] is None:
            subtree_ranges[node][0] = order
            order += 1
        else:
            subtree_ranges[node][1] = order
    return subtree_ranges


def main():
    n, m = [int(x) for x in sys.stdin.readline().split()]
    tree = [[] for _ in range(n)]
    bosses = [int(x) for x in sys.stdin.readline().split()]
    for employee, boss in enumerate(bosses):
        if boss != -1:
            tree[boss - 1].append(employee)
    subtree_ranges = euler_tour_technique(tree, 0)
    fenwick = fenwicktree.FenwickTree(n + 1)
    for _ in range(m):
        query = [int(x) for x in sys.stdin.readline().split()]
        if query[0] == 1:
            _, i, w = query
            beg, end = subtree_ranges[i - 1]
            fenwick.update(beg, w)
            fenwick.update(end, -w)
        else:
            i = query[1]
            pos = subtree_ranges[i - 1][0]
            print(fenwick.query(0, pos + 1))


if __name__ == '__main__':
    main()

• Dependency: teflib.fenwicktree.FenwickTree, teflib.tgraph.dfs