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You are given two distinct non-negative integers x๐‘ฅ and y๐‘ฆ. Consider two infinite sequences a1,a2,a3,โ€ฆ๐‘Ž1,๐‘Ž2,๐‘Ž3,โ€ฆ and b1,b2,b3,โ€ฆ๐‘1,๐‘2,๐‘3,โ€ฆ, wherean=nโŠ•x๐‘Ž๐‘›=๐‘›โŠ•๐‘ฅ;bn=nโŠ•y๐‘๐‘›=๐‘›โŠ•๐‘ฆ.Here, xโŠ•y๐‘ฅโŠ•๐‘ฆ denotes the bitwise XOR operation of integers x๐‘ฅ and y๐‘ฆ.For example, with x=6๐‘ฅ=6, the first 88 elements of sequence a๐‘Ž will look as follows: [7,4,5,2,3,0,1,14,โ€ฆ][7,4,5,2,3,0,1,14,โ€ฆ]. Note that the indices of elements start with 11.Your task is to find the length of the longest common subsegmentโ€ โ€  of sequences a๐‘Ž and b๐‘. In other words, find the maximum integer m๐‘š such that ai=bj,ai+1=bj+1,โ€ฆ,ai+mโˆ’1=bj+mโˆ’1๐‘Ž๐‘–=๐‘๐‘—,๐‘Ž๐‘–+1=๐‘๐‘—+1,โ€ฆ,๐‘Ž๐‘–+๐‘šโˆ’1=๐‘๐‘—+๐‘šโˆ’1 for some i,jโ‰ฅ1๐‘–,๐‘—โ‰ฅ1.โ€ โ€ A subsegment of sequence p๐‘ is a sequence pl,pl+1,โ€ฆ,pr๐‘๐‘™,๐‘๐‘™+1,โ€ฆ,๐‘๐‘Ÿ, where 1โ‰คlโ‰คr1โ‰ค๐‘™โ‰ค๐‘Ÿ.InputEach test consists of multiple test cases. The first line contains a single integer t๐‘ก (1โ‰คtโ‰ค1041โ‰ค๐‘กโ‰ค104)ย โ€” the number of test cases. The description of the test cases follows.The only line of each test case contains two integers x๐‘ฅ and y๐‘ฆ (0โ‰คx,yโ‰ค109,xโ‰ y0โ‰ค๐‘ฅ,๐‘ฆโ‰ค109,๐‘ฅโ‰ ๐‘ฆ)ย โ€” the parameters of the sequences.OutputFor each test case, output a single integerย โ€” the length of the longest common subsegment.ExampleinputCopy40 112 457 37316560849 14570961outputCopy18433554432NoteIn the first test case, the first 77 elements of sequences a๐‘Ž and b๐‘ are as follows:a=[1,2,3,4,5,6,7,โ€ฆ]๐‘Ž=[1,2,3,4,5,6,7,โ€ฆ]b=[0,3,2,5,4,7,6,โ€ฆ]๐‘=[0,3,2,5,4,7,6,โ€ฆ]It can be shown that there isn't a positive integer k๐‘˜ such that the sequence [k,k+1][๐‘˜,๐‘˜+1] occurs in b๐‘ as a subsegment. So the answer is 11.In the third test case, the first 2020 elements of sequences a๐‘Ž and b๐‘ are as follows:a=[56,59,58,61,60,63,62,49,48,51,50,53,52,55,54,41, 40, 43, 42,45,โ€ฆ]๐‘Ž=[56,59,58,61,60,63,62,49,48,51,50,53,52,55,54,41, 40, 43, 42,45,โ€ฆ]b=[36,39,38,33,32,35,34,45,44,47,46,41, 40, 43, 42,53,52,55,54,49,โ€ฆ]๐‘=[36,39,38,33,32,35,34,45,44,47,46,41, 40, 43, 42,53,52,55,54,49,โ€ฆ]It can be shown that one of the longest common subsegments is the subsegment [41,40,43,42][41,40,43,42] with a length of 44.

Question

You are given two distinct non-negative integers x๐‘ฅ and y๐‘ฆ. Consider two infinite sequences a1,a2,a3,โ€ฆ๐‘Ž1,๐‘Ž2,๐‘Ž3,โ€ฆ and b1,b2,b3,โ€ฆ๐‘1,๐‘2,๐‘3,โ€ฆ, wherean=nโŠ•x๐‘Ž๐‘›=๐‘›โŠ•๐‘ฅ;bn=nโŠ•y๐‘๐‘›=๐‘›โŠ•๐‘ฆ.Here, xโŠ•y๐‘ฅโŠ•๐‘ฆ denotes the bitwise XOR operation of integers x๐‘ฅ and y๐‘ฆ.For example, with x=6๐‘ฅ=6, the first 88 elements of sequence a๐‘Ž will look as follows: [7,4,5,2,3,0,1,14,โ€ฆ][7,4,5,2,3,0,1,14,โ€ฆ]. Note that the indices of elements start with 11.Your task is to find the length of the longest common subsegmentโ€ โ€  of sequences a๐‘Ž and b๐‘. In other words, find the maximum integer m๐‘š such that ai=bj,ai+1=bj+1,โ€ฆ,ai+mโˆ’1=bj+mโˆ’1๐‘Ž๐‘–=๐‘๐‘—,๐‘Ž๐‘–+1=๐‘๐‘—+1,โ€ฆ,๐‘Ž๐‘–+๐‘šโˆ’1=๐‘๐‘—+๐‘šโˆ’1 for some i,jโ‰ฅ1๐‘–,๐‘—โ‰ฅ1.โ€ โ€ A subsegment of sequence p๐‘ is a sequence pl,pl+1,โ€ฆ,pr๐‘๐‘™,๐‘๐‘™+1,โ€ฆ,๐‘๐‘Ÿ, where 1โ‰คlโ‰คr1โ‰ค๐‘™โ‰ค๐‘Ÿ.InputEach test consists of multiple test cases. The first line contains a single integer t๐‘ก (1โ‰คtโ‰ค1041โ‰ค๐‘กโ‰ค104)ย โ€” the number of test cases. The description of the test cases follows.The only line of each test case contains two integers x๐‘ฅ and y๐‘ฆ (0โ‰คx,yโ‰ค109,xโ‰ y0โ‰ค๐‘ฅ,๐‘ฆโ‰ค109,๐‘ฅโ‰ ๐‘ฆ)ย โ€” the parameters of the sequences.OutputFor each test case, output a single integerย โ€” the length of the longest common subsegment.ExampleinputCopy40 112 457 37316560849 14570961outputCopy18433554432NoteIn the first test case, the first 77 elements of sequences a๐‘Ž and b๐‘ are as follows:a=[1,2,3,4,5,6,7,โ€ฆ]๐‘Ž=[1,2,3,4,5,6,7,โ€ฆ]b=[0,3,2,5,4,7,6,โ€ฆ]๐‘=[0,3,2,5,4,7,6,โ€ฆ]It can be shown that there isn't a positive integer k๐‘˜ such that the sequence [k,k+1][๐‘˜,๐‘˜+1] occurs in b๐‘ as a subsegment. So the answer is 11.In the third test case, the first 2020 elements of sequences a๐‘Ž and b๐‘ are as follows:a=[56,59,58,61,60,63,62,49,48,51,50,53,52,55,54,41, 40, 43, 42,45,โ€ฆ]๐‘Ž=[56,59,58,61,60,63,62,49,48,51,50,53,52,55,54,41, 40, 43, 42,45,โ€ฆ]b=[36,39,38,33,32,35,34,45,44,47,46,41, 40, 43, 42,53,52,55,54,49,โ€ฆ]๐‘=[36,39,38,33,32,35,34,45,44,47,46,41, 40, 43, 42,53,52,55,54,49,โ€ฆ]It can be shown that one of the longest common subsegments is the subsegment [41,40,43,42][41,40,43,42] with a length of 44.

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Solution

The problem is asking to find the longest common subsegment of two sequences. The sequences are generated by taking the XOR of each index with two distinct non-negative integers x and y.

Here are the steps to solve this problem:

  1. Understand the XOR operation: XOR is a binary operation that takes two bit patterns of equal length and performs the logical exclusive OR operation on each pair of corresponding bits. The result in each position is 1 if only the first bit is 1 or only the second bit is 1, but will be 0 if both are

This problem has been solved

Similar Questions

B. XOR Sequences

You are given an array ๐ดA of size ๐‘N.You can rearrange the elements of ๐ดA as you want. After that, construct an array ๐ตB of size ๐‘N as:๐ต1=๐ด1B 1โ€‹ =A 1โ€‹ ;๐ต๐‘–=๐ต๐‘–โˆ’1โŠ•๐ด๐‘–B iโ€‹ =B iโˆ’1โ€‹ โŠ•A iโ€‹ for all 2โ‰ค๐‘–โ‰ค๐‘2โ‰คiโ‰คN, where โŠ•โŠ• denotes the bitwise XOR operator.Find a rearrangement of ๐ดA such that ๐ต๐‘–โ‰ 0B iโ€‹ ๎€ =0 for all 1โ‰ค๐‘–โ‰ค๐‘1โ‰คiโ‰คN.Input FormatThe first line of input will contain a single integer ๐‘‡T, denoting the number of test cases.Each test case consists of multiple lines of input.The first line of each test case contains ๐‘N, the size of the array ๐ดA.The second line of each test case contains ๐‘N space-separated integers : ๐ด1,๐ด2,โ€ฆ,๐ด๐‘A 1โ€‹ ,A 2โ€‹ ,โ€ฆ,A Nโ€‹ .Output FormatFor each test case, output on a new line, ๐‘N space-separated integers denoting the rearrangement of ๐ดA satisfying the conditions.In case no such rearrangement exists, print โˆ’1โˆ’1 instead.Constraints1โ‰ค๐‘‡โ‰ค2โ‹…1041โ‰คTโ‰ค2โ‹…10 4 1โ‰ค๐‘โ‰ค2โ‹…1051โ‰คNโ‰ค2โ‹…10 5 1โ‰ค๐ด๐‘–โ‰ค1091โ‰คA iโ€‹ โ‰ค10 9 The sum of ๐‘N over all test cases does not exceed 2โ‹…1052โ‹…10 5 .Sample 1:InputOutput431 2 351 2 3 4 531 2 211-11 2 4 3 51 2 21Explanation:Test case 11 : It can be shown that it's impossible to rearrange ๐ดA in a valid way.Test case 22 : A possible rearrangement of array ๐ดA is [1,2,4,3,5][1,2,4,3,5] and the corresponding array ๐ตB is [1,3,7,4,1][1,3,7,4,1]. Here ๐ต๐‘–โ‰ 0B iโ€‹ ๎€ =0 for all 1โ‰ค๐‘–โ‰ค๐‘1โ‰คiโ‰คN.

Given N, print the XOR of all numbers between (1-N).

A certain number 1โ‰คxโ‰ค1091โ‰ค๐‘ฅโ‰ค109 is chosen. You are given two integers a๐‘Ž and b๐‘, which are the two largest divisors of the number x๐‘ฅ. At the same time, the condition 1โ‰คa<b<x1โ‰ค๐‘Ž<๐‘<๐‘ฅ is satisfied.

You are given an array of integers. Find the XOR of all the pairwise sums formed by the elements of the array.Input FormatThe first line of input contains T - the number of test cases. It is followed by 2T lines, the first line contains N - the size of the array. The second line contains the elements of the array.Output FormatFor each test case, print the XOR product of all the pairwise sums of the elements from the array, separated by a newline.Constraints10 points1 <= T <= 1001 <= N <= 10000 <= A[i] <= 10540 points1 <= T <= 1001 <= N <= 1050 <= A[i] <= 105ExampleInput254 10 54 11 8615 35 25 10 15 12Output118120ExplanationTest-Case 1All the pairwise sums formed with 4 are (4 + 4), (4 + 10), (4 + 54), (4 + 11), (4 + 8) = 8, 14, 58, 15, 12All the pairwise sums formed with 10 are (10 + 4), (10 + 10), (10 + 54), (10 + 11), (10 + 8) = 14, 20, 64, 21, 18All the pairwise sums formed with 54 are (54 + 4), (54 + 10), (54 + 54), (54 + 11), (54 + 8) = 58, 64, 108, 65, 62All the pairwise sums formed with 11 are (11 + 4), (11 + 10), (11 + 54), (11 + 11), (11 + 8) = 15, 21, 65, 22, 19All the pairwise sums formed with 8 are (8 + 4), (8 + 10), (8 + 54), (8 + 11), (8 + 8) = 12, 18, 62, 19, 16XOR of all the above sums = (8 ^ 14 ^ 58 ^ 15 ^ 12) ^ (14 ^ 20 ^ 64 ^ 21 ^ 18) ^ (58 ^ 64 ^ 108 ^ 65 ^ 62) ^ (15 ^ 21 ^ 65 ^ 22 ^ 19) ^ (12 ^ 18 ^ 62 ^ 19 ^ 16) = 118

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