KGSS - Maximum Sum

You are given a sequence A[1], A[2], ..., A[N] ( 0 ≤ A[i] ≤ 10^8 , 2 ≤ N ≤ 10^5 ). There are two types of operations and they are defined as follows:


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.


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].


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 the maximum sum mentioned above, in a separate line, for each Query.


1 2 3 4 5
Q 2 4
Q 2 5
U 1 6
Q 1 5
U 1 7
Q 1 5


Warning: large Input/Output data, be careful with certain languages

hide comments
mayank goyal: 2013-06-19 12:43:54

Can anyone look at my code plz..I am getting TLE.Link to my code is

mayank goyal: 2013-06-19 12:21:35

getting TLE using segment trees in java

Swarnaprakash: 2013-03-13 18:24:58

Sabarinath (npsabari@) and Nikola Jovanovic (randomusername@)

I verified the input constraints and my solution and the number of elements in less than 10^5.

Your solutions failed because you had assumed that the data structure you used will contain atmost twice the number of elements. It will actually contain twice the nearest power of 2 greater than n.
I took your solutions and fixed that and retained 10^5 and it got accepted.

RandomUsername: 2013-02-28 11:47:45

@npsabari's comment is true. I had the same problem with N>10^5. Just make the array size 2*10^5 and it will work.

Last edit: 2013-02-28 11:48:30
Tushar Makkar (Retired): 2013-01-18 14:15:29

Last edit: 2013-08-06 12:19:17
Janani: 2012-12-30 18:39:38

Should this be done using segment tree?

npsabari: 2012-12-12 19:44:58

Careful.. number of integers in the array is > 10^5..

Haidar Abboud: 2012-07-23 18:00:16

piece of cake

sandeep pandey: 2012-04-24 02:04:56

Nice One..:)

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