Codeforces Round 830 (Div. 2) |
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Finished |
This is the easy version of the problem. The only difference is that in this version $$$q = 1$$$.
You are given an array of integers $$$a_1, a_2, \ldots, a_n$$$.
The cost of a subsegment of the array $$$[l, r]$$$, $$$1 \leq l \leq r \leq n$$$, is the value $$$f(l, r) = \operatorname{sum}(l, r) - \operatorname{xor}(l, r)$$$, where $$$\operatorname{sum}(l, r) = a_l + a_{l+1} + \ldots + a_r$$$, and $$$\operatorname{xor}(l, r) = a_l \oplus a_{l+1} \oplus \ldots \oplus a_r$$$ ($$$\oplus$$$ stands for bitwise XOR).
You will have $$$q = 1$$$ query. Each query is given by a pair of numbers $$$L_i$$$, $$$R_i$$$, where $$$1 \leq L_i \leq R_i \leq n$$$. You need to find the subsegment $$$[l, r]$$$, $$$L_i \leq l \leq r \leq R_i$$$, with maximum value $$$f(l, r)$$$. If there are several answers, then among them you need to find a subsegment with the minimum length, that is, the minimum value of $$$r - l + 1$$$.
Each test consists of multiple test cases. The first line contains an integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases. The description of test cases follows.
The first line of each test case contains two integers $$$n$$$ and $$$q$$$ ($$$1 \leq n \leq 10^5$$$, $$$q = 1$$$) — the length of the array and the number of queries.
The second line of each test case contains $$$n$$$ integers $$$a_1, a_2, \ldots, a_n$$$ ($$$0 \leq a_i \leq 10^9$$$) — array elements.
$$$i$$$-th of the next $$$q$$$ lines of each test case contains two integers $$$L_i$$$ and $$$R_i$$$ ($$$1 \leq L_i \leq R_i \leq n$$$) — the boundaries in which we need to find the segment.
It is guaranteed that the sum of $$$n$$$ over all test cases does not exceed $$$2 \cdot 10^5$$$.
It is guaranteed that $$$L_1 = 1$$$ and $$$R_1 = n$$$.
For each test case print $$$q$$$ pairs of numbers $$$L_i \leq l \leq r \leq R_i$$$ such that the value $$$f(l, r)$$$ is maximum and among such the length $$$r - l + 1$$$ is minimum. If there are several correct answers, print any of them.
61 101 12 15 101 23 10 2 41 34 10 12 8 31 45 121 32 32 32 101 57 10 1 0 1 0 1 01 7
1 1 1 1 1 1 2 3 2 3 2 4
In the first test case, $$$f(1, 1) = 0 - 0 = 0$$$.
In the second test case, $$$f(1, 1) = 5 - 5 = 0$$$, $$$f(2, 2) = 10 - 10 = 0$$$. Note that $$$f(1, 2) = (10 + 5) - (10 \oplus 5) = 0$$$, but we need to find a subsegment with the minimum length among the maximum values of $$$f(l, r)$$$. So, only segments $$$[1, 1]$$$ and $$$[2, 2]$$$ are the correct answers.
In the fourth test case, $$$f(2, 3) = (12 + 8) - (12 \oplus 8) = 16$$$.
There are two correct answers in the fifth test case, since $$$f(2, 3) = f(3, 4)$$$ and their lengths are equal.
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