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
hide comments
amar_shukla1:
20200518 13:30:23
easy question,But it took me 2 hours and I understood that my implementation was shit. 

abhishek_251:
20200429 10:43:31
0.06 

fighter_4:
20200426 07:16:20
just little bit tricky,but can be done easily ,, one go ,in 0.06 :D, 

pas7582128:
20191226 07:47:43
This one is easiest segment tree problem. Best for newbies. 

urielguz33:
20191226 02:53:47
Nice problem. You can use a priority queue for getting the greatest and second greatest :) 

ashik_01:
20191207 08:09:27
nice one! 

farazradfar125:
20191203 06:27:26
AC on first try 

deadly_sec:
20191006 18:15:10
AC IN ONE GO.


chirayu_555:
20190820 11:33:42
AC in single go..!! A must practice problem for segment trees. 

nitish1603:
20190624 20:01:05
AC in one go >> awsm problem learnt segment 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 