#5741. CSES2166 前缀和查询
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CSES2166 前缀和查询
Prefix Sum Queries
Given an array of n integers, your task is to process q queries of the following types:
update the value at position k to u
what is the maximum prefix sum in range [a,b]?
Empty prefixes (with sum 0) are allowed.
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
Example
Input
8 4
1 2 -1 3 1 -5 1 4
2 2 6
1 4 -2
2 2 6
2 3 4
Output
5
2
0