Interactive MST Solution Codechef -
SOLUTION
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There is a hidden undirected connected graph with nodes and edges numbered , and a hidden permutation of edges. The graph doesn't contain any self loops or multiple edges.
You only know the value of and . You can ask queries. In one query, you give the judge a vector of size consisting of integers in the range . The judge returns integers , such that the edges numbered form a minimum spanning tree of the graph, if the edge numbered had a weight for each . Note that the judge can print the edges in any order, and if there are multiple minimum spanning trees, the judge may print any one of them.
You need to find the hidden permutation in at most queries, or claim that it can't be found uniquely no matter how many queries you're allowed to make.
We have a proof that if it's possible to find the permutation in finitely many queries, then it is possible in at most queries.
Interaction
- First, you should read a line containing the subtask number (, , or ).
- Then, read the number of test cases.
- For each test case, first read the values of and .
- To make a query, you should output a question mark, followed by space-separated integers denoting the weights: .
- If the query format is incorrect, or if some weight exceeds , or the number of queries (including this query) has exceeded , the judge prints a single integer and quits with a wrong answer verdict. In this case, you must also terminate your program.
- Otherwise, the judge prints space-separated integers : .
- If you have found the permutation , you should output an exclamation mark followed by space-separated integers : . Else, if you have reached the conclusion that the hidden permutation can not be found, print exclamation mark followed by : .
- If your answer is incorrect, the judge prints and exits. In this case, you must terminate your program as well. Else, the judge prints , and you should move to the next testcase(if any).
Note that whenever the judge prints , you should immediately terminate your program to receive a Wrong Answer verdict; otherwise, you may receive any verdict. Don't forget to flush the output after printing each line!
Constraints
- The sum of over all test cases doesn't exceed .
Subtasks
- Subtask 1(8 points) : is a tree
- Subtask 2(21 points) : is a cycle
- Subtask 3(71 points) : No additional constraints.
Example
In this example, the hidden graph has edges , and numbered respectively, in all testcases. In the first testcase, and in the second, . The third testcase shouldn't be read as the judge prints in testcase .
You Grader
2 # Subtask 2
3 # 3 testcases
3 3 # n = 3, m = 3
? 2 3 2
2 1 # The permuted weights would be [3, 2, 2]
? 2 3 2
1 2 # For the same vector w, judge's output can be different.
! 2 0 1
1 # Correct output. Note that this is merely a lucky guess
3 3 # Next testcase, n = 3, m = 3
? 2 2 1
0 2
! 1 0 2
-1 # Incorrect output! Judge exits now.
You should also
terminate here.
SOLUTION
” CLICK HERE “
Details
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Junglee Games

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