Problem on Tree

AtCoder

IDrelay_k

Time2000ms

Memory256MB

Difficulty—

There is a tree with $N$ vertices, numbered $1$ through $N$. The $i$\-th of the $N-1$ edges connects the vertices $p_i$ and $q_i$. Among the sequences of distinct vertices $v_1, v_2, ..., v_M$ that satisfy the following condition, find the maximum value of $M$. * For every $1 \leq i < M$, the path connecting the vertices $v_i$ and $v_{i+1}$ do not contain any vertex in $v$, except for $v_i$ and $v_{i+1}$. ## Constraints * $2 \leq N \leq 10^5$ * $1 \leq p_i, q_i \leq N$ * The given graph is a tree. ## Input The input is given from Standard Input in the following format: $N$ $p_1$ $q_1$ $p_2$ $q_2$ : $p_{N-1}$ $q_{N-1}$ [samples]

Samples

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Input #2

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API Response (JSON)

{
  "problem": {
    "name": "Problem on Tree",
    "description": {
      "content": "There is a tree with $N$ vertices, numbered $1$ through $N$. The $i$\\-th of the $N-1$ edges connects the vertices $p_i$ and $q_i$. Among the sequences of distinct vertices $v_1, v_2, ..., v_M$ that sa",
      "description_type": "Markdown"
    },
    "platform": "AtCoder",
    "limit": {
      "time_limit": 2000,
      "memory_limit": 262144
    },
    "difficulty": "None",
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "relay_k"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "There is a tree with $N$ vertices, numbered $1$ through $N$.\nThe $i$\\-th of the $N-1$ edges connects the vertices $p_i$ and $q_i$.\nAmong the sequences of distinct vertices $v_1, v_2, ..., v_M$ that sa...",
      "is_translate": false,
      "language": "English"
    }
  ]
}

Full JSON Raw Segments