Codeforces Round 920 (Div. 3) |
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Finished |
You are given an array $$$a$$$ of $$$n$$$ numbers. There are also $$$q$$$ queries of the form $$$s, d, k$$$.
For each query $$$q$$$, find the sum of elements $$$a_s + a_{s+d} \cdot 2 + \dots + a_{s + d \cdot (k - 1)} \cdot k$$$. In other words, for each query, it is necessary to find the sum of $$$k$$$ elements of the array with indices starting from the $$$s$$$-th, taking steps of size $$$d$$$, multiplying it by the serial number of the element in the resulting sequence.
Each test consists of several testcases. The first line contains one integer $$$t$$$ ($$$1 \le t \le 10^4$$$) — the number of testcases. Next lines contain descriptions of testcases.
The first line of each testcase contains two numbers $$$n, q$$$ ($$$1 \le n \le 10^5, 1 \le q \le 2 \cdot 10^5$$$) — the number of elements in the array $$$a$$$ and the number of queries.
The second line contains $$$n$$$ integers $$$a_1, ... a_n$$$ ($$$-10^8 \le a_1, ..., a_n \le 10^8$$$) — elements of the array $$$a$$$.
The next $$$q$$$ lines each contain three integers $$$s$$$, $$$d$$$, and $$$k$$$ ($$$1 \le s, d, k \le n$$$, $$$s + d\cdot (k - 1) \le n$$$ ).
It is guaranteed that the sum of $$$n$$$ over all testcases does not exceed $$$10^5$$$, and that the sum of $$$q$$$ over all testcases does not exceed $$$2 \cdot 10^5 $$$.
For each testcase, print $$$q$$$ numbers in a separate line — the desired sums, separated with space.
53 31 1 21 2 22 2 11 1 23 1-100000000 -100000000 -1000000001 1 35 31 2 3 4 51 2 32 3 21 1 53 1100000000 100000000 1000000001 1 37 734 87 5 42 -44 66 -322 2 24 3 11 3 26 2 15 2 22 5 26 1 2
5 1 3 -600000000 22 12 55 600000000 171 42 118 66 -108 23 2
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