Codeforces Round 440 (Div. 1, based on Technocup 2018 Elimination Round 2)
B
Something with XOR Queries
Codeforces
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原题
← AC →
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This is an interactive problem.

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Jury has hidden a permutation $*p*$ of integers from $0$ to $*n* - 1$. You know only the length $*n*$. Remind that in permutation all integers are distinct.

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Let $*b*$ be the inverse permutation for $*p*$, i.e. $*p*_{*b*_{*i*}} = *i*$ for all $*i*$. The only thing you can do is to ask xor of elements $*p*_{*i*}$ and $*b*_{*j*}$, printing two indices $*i*$ and $*j*$ (not necessarily distinct). As a result of the query with indices $*i*$ and $*j*$ you'll get the value image, where image denotes the xor operation. You can find the description of xor operation in notes.

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Note that some permutations can remain indistinguishable from the hidden one, even if you make all possible $*n*^{2}$ queries. You have to compute the number of permutations indistinguishable from the hidden one, and print one of such permutations, making no more than $2*n*$ queries.

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The hidden permutation does not depend on your queries.

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Input

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The first line contains single integer $*n*$ ($1 ≤ *n* ≤ 5000$) — the length of the hidden permutation. You should read this integer first.

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Output

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When your program is ready to print the answer, print three lines.

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In the first line print "!".

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In the second line print single integer $*answers*_*cnt*$ — the number of permutations indistinguishable from the hidden one, including the hidden one.

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In the third line print $*n*$ integers $*p*_{0}, *p*_{1}, ..., *p*_{*n* - 1}$ ($0 ≤ *p*_{*i*} < *n*$, all $*p*_{*i*}$ should be distinct) — one of the permutations indistinguishable from the hidden one.

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Your program should terminate after printing the answer.

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Interaction

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To ask about xor of two elements, print a string "? i j", where $*i*$ and $*j*$ — are integers from $0$ to $*n* - 1$ — the index of the permutation element and the index of the inverse permutation element you want to know the xor-sum for. After that print a line break and make flush operation.

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After printing the query your program should read single integer — the value of image.

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For a permutation of length $*n*$ your program should make no more than $2*n*$ queries about xor-sum. Note that printing answer doesn't count as a query. Note that you can't ask more than $2*n*$ questions. If you ask more than $2*n*$ questions or at least one incorrect question, your solution will get "Wrong answer".

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If at some moment your program reads -1 as an answer, it should immediately exit (for example, by calling exit(0)). You will get "Wrong answer" in this case, it means that you asked more than $2*n*$ questions, or asked an invalid question. If you ignore this, you can get other verdicts since your program will continue to read from a closed stream.

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Your solution will get "Idleness Limit Exceeded", if you don't print anything or forget to flush the output, including for the final answer .

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To flush you can use (just after printing line break):

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  • fflush(stdout) in C++;
  • System.out.flush() in Java;
  • stdout.flush() in Python;
  • flush(output) in Pascal;
  • For other languages see the documentation.
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Hacking

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For hacking use the following format:

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$*n*$

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$*p*_{0}$ $*p*_{1}$ ... $*p*_{*n* - 1}$

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Contestant programs will not be able to see this input.

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Note

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xor operation, or bitwise exclusive OR, is an operation performed over two integers, in which the $*i*$-th digit in binary representation of the result is equal to $1$ if and only if exactly one of the two integers has the $*i*$-th digit in binary representation equal to $1$. For more information, see here.

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In the first example $*p* = [0, 1, 2]$, thus $*b* = [0, 1, 2]$, the values image are correct for the given $*i*, *j*$. There are no other permutations that give the same answers for the given queries.

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The answers for the queries are:

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  • image,
  • image,
  • image,
  • image,
  • image,
  • image.
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In the second example $*p* = [3, 1, 2, 0]$, and $*b* = [3, 1, 2, 0]$, the values image match for all pairs $*i*, *j*$. But there is one more suitable permutation $*p* = [0, 2, 1, 3]$, $*b* = [0, 2, 1, 3]$ that matches all $*n*^{2}$ possible queries as well. All other permutations do not match even the shown queries.

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样例

Input #1
3
0
0
3
2
3
2
Output #1
? 0 0
? 1 1
? 1 2
? 0 2
? 2 1
? 2 0
!
1
0 1 2
InputCopy OutputCopy
Input #2
4
2
3
2
0
2
3
2
0
Output #2
? 0 1
? 1 2
? 2 3
? 3 3
? 3 2
? 2 1
? 1 0
? 0 0
!
2
3 1 2 0
InputCopy OutputCopy
题目信息
题号
871B
时间限制
2 s
内存限制
256 MB

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。