Problem7609--[CSES Problem Set] Prefix Sum Queries

7609: [CSES Problem Set] Prefix Sum Queries

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Time Limit : 1.000 sec  Memory Limit : 256 MiB

Description

Given an array of $n$ integers, your task is to process $q$ queries of the following types:
  1. update the value at position $k$ to $u$
  2. what is the maximum prefix sum in range $[a,b]$?

Input

The first input line has two integers $n$ and $q$: the number of values and queries.
The second line has $n$ integers $x_1,x_2,\dots,x_n$: the array values.
Finally, there are $q$ lines describing the queries. Each line has three integers: either "1 k u" or "2 a b".

Output

Print the result of each query of type 2.

Constraints

$1≤n,q≤2⋅10^5$
$-10^9 \le x_i, u \le 10^9$
$1 \le k \le n$
$1 \le a \le b \le n$

Sample 1 Input

8 4
1 2 -1 3 1 -5 1 4
2 2 6
1 4 -2
2 2 6
2 3 4

Sample 1 Output

5
2
0

HINT

相同题目:CSES 2166

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