|| ||Code Submission Evaluation System
CSES Problem Set
Task | Statistics
CSES - Path Queries
|Time limit:||1.00 s
||Memory limit:||512 MB|
You are given a rooted tree that consists of $n$ nodes. The nodes are numbered $1,2,\ldots,n$, and node $1$ is the root. Each node has a value.
Your task is to process following types of queries:
- change the value of node $s$ to $x$
- calculate the sum of values on the path from the root to node $s$
The first input line contains two integers $n$: the number of nodes and queries. The nodes are numbered $1,2,\ldots,n$.
The next line has $n$ integers $v_1,v_2,\ldots,v_n$: the value of each node.
Then there are $n-1$ lines that describe the edges. Each line contans two integers $a$ and $b$: there is an edge between nodes $a$ and $b$.
Finally, there are $q$ lines that describe the queries. Each query is either of the form "1 $s$ $x$" or "2 $s$".
Print the answer to each query of type 2.
- $1 \le n, q \le 2 \cdot 10^5$
- $1 \le a,b, s \le n$
- $1 \le v_i, x \le 10^9$
4 2 5 2 1
1 3 2