P13036 [HackerEarth] skipping sum 1
普及
题目描述

You are given an array of N integers A[1] , A[2] , ... , A[N] . You have to answer Q queries. Each query consists of 3 integers L, R and K. For each query, you have to find the value of the Skipping Sum in the following manner :

   def skipping_sum(L,R,K) :
          sum = 0
          while L ≤ R :
                sum = sum + A[L]
                L = L + K 
          return sum

Input
The first line consists of 2 space separated integers N and Q. The next line consists of N space separated integers, the i^th integer being A[i]. Then, Q lines follow, each line consisting of 3 space separated integers L, R and K.
Output
Print the answer to each query on a new line.
Constraints
1 ≤ N ≤ 10^5
1 ≤ Q ≤ 10^5
0 ≤ A[i] ≤ 10^5
1 ≤ L ≤ R ≤ N
1 ≤ K ≤ 10

NOTE:
We are using 1-based indexing for array A.

SAMPLE INPUT
8 6
5 4 2 1 7 9 10 9
1 8 1
1 8 2
4 8 9
3 7 2
3 7 3
3 7 4

SAMPLE OUTPUT
47
24
1
19
11
12

Explanation

For query 1 : A[1] + A[2] + A[3] + A[4] + A[5] + A[6] + A[8] = 47
For query 2 : A[1] + A[3] + A[5] + A[7] = 24
For query 3 : A[4] = 1
For query 4 : A[3] + A[5] + A[7] = 19
For query 5 : A[3] + A[6] = 11
For query 6 : A[3] + A[7] = 12

输入格式

见题面

输出格式

见题面

样例输入
8 6 5 4 2 1 7 9 10 9 1 8 1 1 8 2 4 8 9 3 7 2 3 7 3 3 7 4 SAMPLE
样例输出
47 24 1 19 11 12