RANGESUM  Range Sum
Problem Statement
You are initially given an array of N integers ( 1<=N<=10^{5} ). Given this array, you have to perform 2 kinds of operations :
(i) Operation 1 : Op1( l, r )
You are given 2 integers l and r. ( 1 <= l <= r <= current size of the array ). You need to return the sum of all the elements with indices between l and r ( both inclusive ). That is, if the elements currently in the array are a_{1}, a_{2}, a_{3}.... a_{n}, you need to return the following sum : a_{l} + a_{l+1} + a_{l+2} ... + a_{r}.
(ii) Operation 2 : Op2( x )
You are given a single integer x ( x <= 10^{9} ). Add this element to the beginning of the array. After this operation, x will now become a_{1}, the old a_{1} will now become a_{2}, and so on. The size of the array will increase by 1.
Input
The first line contains a single integer N ( 1 <= N <= 10^{5} ), the number of elements initially in the array.
This is followed by a line containing N space separated integers, a_{1} a_{2} .... a_{N}. ( a_{i} <= 10^{9} )
The next line contains a single integer Q, the number of operations you will be asked to perform. ( 1 <= Q <= 10^{5} )
Q lines of input follow. Each such line starts with either the number 1 or the number 2. This indicates the type of operation that you are required to perform. The format of these queries are as follows :
1 l r : Carry out operation 1 with arguments l and r. ( 1 <= l <= r <= current size of the array )
That is, return the sum of the following array elements : a_{l} + a_{l+1} ... + a_{r}
2 x : Carry out operation 2 with the argument x. ( x <= 10^{9} )
That is, add the value x at the beginning of the array.
Output
For each query of type 1, output the return value on a new line. No output needs to be printed for queries of type 2.
Example
Input #1: 10
1 2 3 4 5 6 7 8 9 10
4
1 1 10
1 1 1
1 10 10
1 2 7
Output #1:
55
1
10
27
Input #2:
5
6 7 8 9 10
9
2 5
2 4
1 2 7
2 3
2 2
2 1
1 1 10
1 1 1
1 10 10
Output #2:
45
55
1
10
hide comments
sharath1999:
20201001 22:38:26
If you wanna do it with segment tree just input the array into segment tree in reverse and add elements in the end 

stunner2k18:
20191031 14:28:34
AC in one Go!


veerendrasd_9:
20190527 12:25:14
use prefix sum array. range sum in O(1) and adding in O(n).


julkas:
20181227 13:44:28
Without ... :). Not so bad! 

mag1x_:
20180623 12:12:25
Take input array invert it and prefix sum :) 

vivek_dwivedi:
20180613 21:05:01
Need some help !!


king_cat:
20180514 09:29:57
Use long long int!! 

gamapro:
20180417 20:23:40
Never use printf, it cause me 5 WRONG ANSWER


dipankar12:
20180401 19:07:46
sqrt+dcmp works 

karthik_vg:
20171103 05:23:07
never use accumalate in c++ it costed me 3 WA. 
Added by:  Gowri Sundaram 
Date:  20130411 
Time limit:  2s 
Source limit:  50000B 
Memory limit:  1536MB 
Cluster:  Cube (Intel G860) 
Languages:  All except: ASM64 