Codeforces Round 766 (Div. 2)

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ContestId
Name
Phase
Frozen
Duration (Seconds)
Relative Time
Start Time
1627 Codeforces Round 766 (Div. 2) FINISHED False 7200 134148323 Jan. 15, 2022, 2:35 p.m.

Problems

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Name
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( 16207 ) C Not Assigning PROGRAMMING constructive algorithms dfs and similar number theory trees

You are given a tree of n vertices numbered from 1 to n , with edges numbered from 1 to n-1 . A tree is a connected undirected graph without cycles. You have to assign integer weights to each edge of the tree, such that the resultant graph is a prime tree. A prime tree is a tree where the weight of every path consisting of one or two edges is prime. A path should not visit any vertex twice. The weight of a path is the sum of edge weights on that path. Consider the graph below. It is a prime tree as the weight of every path of two or less edges is prime. For example, the following path of two edges: 2 to 1 to 3 has a weight of 11 + 2 = 13 , which is prime. Similarly, the path of one edge: 4 to 3 has a weight of 5 , which is also prime. Print any valid assignment of weights such that the resultant tree is a prime tree. If there is no such assignment, then print -1 . It can be proven that if a valid assignment exists, one exists with weights between 1 and 10^5 as well. The input consists of multiple test cases. The first line contains an integer t ( 1 <= q t <= q 10^4 ) -- the number of test cases. The description of the test cases follows. The first line of each test case contains one integer n ( 2 <= q n <= q 10^5 ) -- the number of vertices in the tree. Then, n-1 lines follow. The i -th line contains two integers u and v ( 1 <= q u, v <= q n ) denoting that edge number i is between vertices u and v . It is guaranteed that the edges form a tree. It is guaranteed that the sum of n over all test cases does not exceed 10^5 . For each test case, if a valid assignment exists, then print a single line containing n-1 integers a_1, a_2, ... , a_{n-1} ( 1 <= q a_i <= 10^5 ), where a_i denotes the weight assigned to the edge numbered i . Otherwise, print -1 . If there are multiple soluti

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Codeforces Round #766 (Div. 2) Editorial

Submissions

Submission Id
Author(s)
Index
Submitted
Verdict
Language
Test Set
Tests Passed
Time taken (ms)
Memory Consumed (bytes)
Tags
Rating
142876133 ruban C Jan. 15, 2022, 4:26 p.m. OK Delphi TESTS 30 93 208998400
142874133 Pluto_Xz C Jan. 15, 2022, 4:21 p.m. OK GNU C++14 TESTS 30 62 2457600
142909877 342zhuyongqi C Jan. 16, 2022, 3:38 a.m. OK GNU C++14 TESTS 30 62 9625600
142879573 L2c C Jan. 15, 2022, 4:34 p.m. OK GNU C++14 TESTS 30 77 7577600
142909954 342zhuyongqi C Jan. 16, 2022, 3:39 a.m. OK GNU C++14 TESTS 30 77 9625600
142909820 bfsdw1qaz C Jan. 16, 2022, 3:37 a.m. OK GNU C++14 TESTS 30 77 11980800
142910827 Vanthoci C Jan. 16, 2022, 4 a.m. OK GNU C++14 TESTS 30 78 1638400
142904238 HalfStar C Jan. 16, 2022, 12:22 a.m. OK GNU C++14 TESTS 30 78 6144000
142908067 wcarry afmafk chen_qian C Jan. 16, 2022, 2:50 a.m. OK GNU C++14 TESTS 30 78 7577600
142904979 zouguangchen C Jan. 16, 2022, 1 a.m. OK GNU C++14 TESTS 30 78 7987200
142905707 CCSU_Wine C Jan. 16, 2022, 1:31 a.m. OK GNU C++14 TESTS 30 78 9625600
142876284 saratcsss C Jan. 15, 2022, 4:26 p.m. OK .NET Core C# TESTS 30 312 27136000

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