KGSS  Maximum Sum
This will be indicated in the input by a 'U' followed by space and then two integers i and x.
U i x, 1 ≤ i ≤ N, and x, 0 ≤ x ≤ 10^8.
This operation sets the value of A[i] to x.
Query:This will be indicated in the input by a 'Q' followed by a single space and then two integers i and j.
Q x y, 1 ≤ x < y ≤ N.
You must find i and j such that x ≤ i, j ≤ y and i != j, such that the sum A[i]+A[j] is maximized. Print the sum A[i]+A[j].
Input
The first line of input consists of an integer N representing the length of the sequence. Next line consists of N space separated integers A[i]. Next line contains an integer Q, Q ≤ 10^5, representing the number of operations. Next Q lines contain the operations.
Output
Output the maximum sum mentioned above, in a separate line, for each Query.
Example
Input: 5 1 2 3 4 5 6 Q 2 4 Q 2 5 U 1 6 Q 1 5 U 1 7 Q 1 5 Output: 7 9 11 12
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alaa seb:
20170324 23:46:21
my first segment tree .. AC in one go :)


shahzada:
20170314 13:56:05
RE(SIGSEGV)  Scanf


nilabja16180:
20170309 11:29:26
AC in ONE GO! 

gauravgb21:
20170228 21:28:02
AC in one go!!! 

akshay31057:
20170114 21:12:57
Excellent problem!!!!!go for structure array...


souvik23:
20170103 06:11:25
@gustavoaca1997 : The max size is 10^5 which is not a power of 2 ...... You have to take the nearest power of 2 greater than 10^5 i.e. 131072 and so your tree size must be 2*131072 which is > 2*10^5.That's why it didn't work:) 

lincolnbf:
20161007 01:51:21
gustavoaca the size of seg tree can go upto 4N for an array of size N. 

gustavoaca1997:
20160915 07:34:13
got RE because the size of my tree was 2 * 100000 + somethingElse. I chose that size because of theory of Segment Tree ("there are total 2 * n  1 nodes"). I had to put 3 * 100000. Can someone explain me why 2 * 100000 does not work? 

S. M. Shakir Ahsan Romeo:
20160726 20:15:45
Easy 

Dilpreet:
20160720 21:39:12
Take care of the space of the array and tree

Added by:  Swarnaprakash 
Date:  20090110 
Time limit:  1s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ERL JSRHINO NODEJS PERL6 VB.NET 
Resource:  Kurukshetra 09 OPC 