[ICPC 2021 Macao R] Colorful Tree

Luogu
IDLGP9665
Time6000ms
Memory512MB
DifficultyP6
线段树2021O2优化树论ICPC澳门
Your task is to maintain a colorful tree and process queries. At the beginning, there is only one vertex numbered $1$ with color $C$ on the tree. Then there are $q$ operations of two types coming in order: - $0$ $x$ $c$ $d$: Add a new vertex indexed $(n+1)$ with color $c$ to the tree, where $n$ is the current number of existing vertices. An edge connecting vertex $x$ and $(n+1)$ with length $d$ will also be added to the tree. - $1$ $x$ $c$: Change the color of vertex $x$ to $c$. After each operation, you should find a pair of vertices $u$ and $v$ ($1 \le u, v \le n$) with $\textbf{different}$ colors in the current tree so that the distance between $u$ and $v$ is as large as possible. The distance between two vertices $u$ and $v$ is the length of the shortest path from $u$ to $v$ on the tree. ## Input There are multiple test cases. The first line of the input contains an integer $T$ indicating the number of test cases. For each test case: The first line of the input contains two integers $q$ and $C$ ($1 \le q \le 5 \times 10^5$, $1 \le C \le q$) indicating the number of operations and the initial color of vertex $1$. For the following $q$ lines, each line describes an operation taking place in order with $3$ or $4$ integers. - If the $i$-th line contains $4$ integers $0$, $x_i$, $c_i$ and $d_i$ ($1 \le x_i \le n$, $1 \le c_i \le q$, $1 \le d \le 10^9$), the $i$-th operation will add a new vertex $(n + 1)$ with color $c_i$ to the tree and connect it to vertex $x_i$ with an edge of length $d_i$. - If the $i$-th line contains $3$ integers $1$, $x_i$ and $c_i$ ($1 \le x_i \le n$, $1 \le c_i \le q$), the $i$-th operation will change the color of vertex $x_i$ to $c_i$. It's guaranteed that the sum of $q$ of all test cases will not exceed $5 \times 10^5$. ## Output For each operation output the maximum distance between two vertices with different colors. If no valid pair exists output $0$ instead. [samples]
Samples
Input #1
2
1 1
0 1 1 1
5 1
0 1 1 1
0 1 2 1
0 3 3 1
1 4 1
1 3 1
Output #1
0
0
2
3
2
0
API Response (JSON)
{
  "problem": {
    "name": "[ICPC 2021 Macao R] Colorful Tree",
    "description": {
      "content": "Your task is to maintain a colorful tree and process queries. At the beginning, there is only one vertex numbered $1$ with color $C$ on the tree. Then there are $q$ operations of two types coming in ",
      "description_type": "Markdown"
    },
    "platform": "Luogu",
    "limit": {
      "time_limit": 6000,
      "memory_limit": 524288
    },
    "difficulty": {
      "LuoguStyle": "P6"
    },
    "is_remote": true,
    "is_sync": true,
    "sync_url": null,
    "sign": "LGP9665"
  },
  "statements": [
    {
      "statement_type": "Markdown",
      "content": "Your task is to maintain a colorful tree and process queries.\n\nAt the beginning, there is only one vertex numbered $1$ with color $C$ on the tree. Then there are $q$ operations of two types coming in ...",
      "is_translate": false,
      "language": "English"
    }
  ]
}
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