Codeforces Round 830 (Div. 2)
C1
Sheikh (Easy version)
Codeforces
1800
原题
← BC2 →
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This is the easy version of the problem. The only difference is that in this version $q = 1$.

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You are given an array of integers $a_1, a_2, \ldots, a_n$.

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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).

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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 $r - l + 1$.

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Input

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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.

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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.

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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.

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$i$-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.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $2 \cdot 10^5$.

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It is guaranteed that $L_1 = 1$ and $R_1 = n$.

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Output

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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.

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Note

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In the first test case, $f(1, 1) = 0 - 0 = 0$.

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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.

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In the fourth test case, $f(2, 3) = (12 + 8) - (12 \oplus 8) = 16$.

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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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样例

Input #1
6
1 1
0
1 1
2 1
5 10
1 2
3 1
0 2 4
1 3
4 1
0 12 8 3
1 4
5 1
21 32 32 32 10
1 5
7 1
0 1 0 1 0 1 0
1 7
Output #1
1 1
1 1
1 1
2 3
2 3
2 4
InputCopy OutputCopy
题目信息
题号
1732C1
时间限制
4 s
内存限制
256 MB
标签
二分
位运算
贪心
双指针

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