Codeforces Global Round 26 |
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Finished |
Two hungry red pandas, Oscar and Lura, have a tree $$$T$$$ with $$$n$$$ nodes. They are willing to perform the following shuffle procedure on the whole tree $$$T$$$ exactly once. With this shuffle procedure, they will create a new tree out of the nodes of the old tree.
After this, Oscar and Lura are left with a new tree $$$T_2$$$. They can only eat leaves and are very hungry, so please find the maximum number of leaves over all trees that can be created in exactly one shuffle.
Note that leaves are all nodes with degree $$$1$$$. Thus, the root may be considered as a leaf if it has only one child.
The first line contains a single integer $$$t$$$ ($$$1 \leq t \leq 10^4$$$) — the number of test cases.
The first line of every test case contains a single integer $$$n$$$ ($$$2 \leq n \leq 2 \cdot 10^5$$$) — the number of nodes within the original tree $$$T$$$.
The next $$$n - 1$$$ lines each contain two integers $$$u$$$ and $$$v$$$ ($$$1 \leq u, v \leq n$$$) — an edge within the original tree $$$T$$$. The given edges form a tree.
The sum of $$$n$$$ over all test cases does not exceed $$$3 \cdot 10^5$$$.
For each test case, output a single integer — the maximum number of leaves achievable with exactly one shuffle procedure on the whole tree.
451 21 32 42 551 22 33 44 561 21 31 41 51 6109 38 110 68 57 84 61 310 12 7
4 3 5 6
In the first test case, it can be shown that the maximum number of leaves is $$$4$$$. To accomplish this, we can start our shuffle with selecting node $$$3$$$ as the new root.
In our second test case, we have a line of five nodes. It can be shown that the maximum number of leaves after one shuffle is $$$3$$$. We can start off with node $$$2$$$, which forces node $$$1$$$ to become a leaf. Then, if we select node $$$4$$$ on the right side, we will also have nodes $$$3$$$ and $$$5$$$ as leaves.
The third test case is a star graph with six nodes. The number of leaves cannot increase, thus our answer will be $$$5$$$ (if we start the shuffling with the original root node).
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