結果
| 問題 | No.806 木を道に |
| ユーザー |
 mnzn
|
| 提出日時 | 2020-04-11 05:12:05 |
| 言語 | C#(csc) (csc 3.9.0) |
| 結果 |
WA
|
| 実行時間 | - |
| コード長 | 9,841 bytes |
| コンパイル時間 | 984 ms |
| コンパイル使用メモリ | 110,848 KB |
| 実行使用メモリ | 52,016 KB |
| 最終ジャッジ日時 | 2024-09-17 08:22:23 |
| 合計ジャッジ時間 | 7,084 ms |
|
ジャッジサーバーID （参考情報） |
judge2 / judge1 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 9 WA * 18 |
コンパイルメッセージ
Microsoft (R) Visual C# Compiler version 3.9.0-6.21124.20 (db94f4cc) Copyright (C) Microsoft Corporation. All rights reserved.
ソースコード
using System;using System.Collections;using System.Collections.Generic;using System.IO;using System.Linq;class Program{static void Main(string[] args){var N = sc.ReadInt();var G = new List<int>[N];var dij = new Dijkstra(N);for (int i = 0; i < N; i++){G[i] = new List<int>();}for (int i = 0; i < N - 1; i++){var x = sc.ReadInt() - 1;var y = sc.ReadInt() - 1;dij.Add(x, y, -1);dij.Add(y, x, -1);}var dist = dij.Calc(0);var p1 = Array.IndexOf(dist, dist.Min());dist = dij.Calc(p1);var diameter = -dist.Min();var ans = N - diameter - 1;Console.WriteLine(ans);}class Dijkstra{public int V { get; set; }public int E { get; set; }public List<Edge>[] G { get; set; }public Dijkstra(int n){this.V = n;this.G = new List<Edge>[V];for (int i = 0; i < V; i++){this.G[i] = new List<Edge>();}}public void Add(int a, int b, long cost = 1){this.G[a].Add(new Edge(b, cost));this.G[b].Add(new Edge(a, cost));this.E++;}public long GetMinCost(int start, int goal){var cost = new long[V];for (int i = 0; i < V; i++) cost[i] = long.MaxValue;cost[start] = 0;var capacity = Math.Max(1, E);var q = new PriorityQueue<P>(capacity, false);q.Enqueue(new P(start, 0));while (q.Count > 0){var p = q.Dequeue();if (p.Cost != cost[p.A]) continue;foreach (var e in this.G[p.A]){if (cost[e.To] > p.Cost + e.Cost){cost[e.To] = p.Cost + e.Cost;q.Enqueue(new P(e.To, cost[e.To]));}}}return cost[goal] == long.MaxValue ? -1 : cost[goal];}public long[] Calc(int start){var visited = new bool[V];var cost = new long[V];for (int i = 0; i < V; i++) cost[i] = long.MaxValue;cost[start] = 0;var capacity = Math.Max(1, E);var q = new PriorityQueue<P>(capacity, false);q.Enqueue(new P(start, 0));while (q.Count > 0){var p = q.Dequeue();visited[p.A] = true;if (p.Cost != cost[p.A]) continue;foreach (var e in this.G[p.A]){if (cost[e.To] > p.Cost + e.Cost && !visited[e.To]){cost[e.To] = p.Cost + e.Cost;q.Enqueue(new P(e.To, cost[e.To]));}}}return cost;}public struct Edge{public int To;public long Cost;public Edge(int to, long cost){this.To = to;this.Cost = cost;}}public struct P : IComparable<P>{public int A;public long Cost;public P(int a, long cost){this.A = a;this.Cost = cost;}public int CompareTo(P other){return this.Cost.CompareTo(other.Cost);}}}class PriorityQueue<T>{public readonly T[] Array;public readonly bool Greater;public int Count { get; private set; } = 0;private IComparer<T> Cmp;public PriorityQueue(int capacity, bool greater = true, IComparer<T> cmp = null){this.Cmp = cmp;if (cmp == null){this.Cmp = Comparer<T>.Default;}this.Array = new T[capacity];this.Greater = greater;}public void Enqueue(T item){this.Array[this.Count] = item;this.Count += 1;this.UpHeap();}public T Dequeue(){this.Swap(0, this.Count - 1);this.Count -= 1;this.DownHeap();return this.Array[this.Count];}public T Peek(){return this.Array[0];}private void UpHeap(){var n = this.Count - 1;while (n != 0){var parent = (n - 1) / 2;if (this.Compare(this.Array[n], this.Array[parent]) > 0){this.Swap(n, parent);n = parent;}else{break;}}}private void DownHeap(){var parent = 0;while (true){var child = 2 * parent + 1;if (child > this.Count - 1) break;if (child < this.Count - 1 && this.Compare(this.Array[child], this.Array[child + 1]) < 0){child += 1;}if (this.Compare(this.Array[parent], this.Array[child]) < 0){this.Swap(parent, child);parent = child;}else{break;}}}private int Compare(T a, T b){var c = this.Cmp.Compare(a, b);if (!this.Greater){c = -c;}return c;}private void Swap(int a, int b){var tmp = this.Array[a];this.Array[a] = this.Array[b];this.Array[b] = tmp;}}static Scanner sc = new Scanner();}class Scanner{string[] S = new string[0];int Index = 0;char[] Separators = new char[] { ' ' };public string Next(){if (this.Index < this.S.Length) return this.S[this.Index++];var line = "";while (line == "") line = Console.ReadLine();this.S = line.Split(this.Separators, StringSplitOptions.RemoveEmptyEntries);if (this.S.Length == 0) return this.Next();this.Index = 0;return this.S[this.Index++];}public string ReadStr(){return this.Next();}public char ReadChar(){return this.Next()[0];}public int ReadInt(){return int.Parse(this.Next());}public uint ReadUInt(){return uint.Parse(this.Next());}public long ReadLong(){return long.Parse(this.Next());}public double ReadDouble(){return double.Parse(this.Next());}public Tuple<int, int> ReadTup(int add = 0){return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add);}public Tuple<long, long> ReadTupLong(int add = 0){return Tuple.Create(this.ReadLong() + add, this.ReadLong() + add);}public Tuple<int, int, int> ReadTup3(int add = 0){return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add);}public Tuple<int, int, int, int> ReadTup4(int add = 0){return Tuple.Create(this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add, this.ReadInt() + add);}public int[] ReadIntArray(int n){var array = new int[n];for (int i = 0; i < array.Length; i++){array[i] = this.ReadInt();}return array;}public long[] ReadLongArray(int n){var array = new long[n];for (int i = 0; i < array.Length; i++){array[i] = this.ReadLong();}return array;}public double[] ReadDoubleArray(int n){var array = new double[n];for (int i = 0; i < array.Length; i++){array[i] = this.ReadDouble();}return array;}public char[] ReadCharArray(int n){var array = new char[n];for (int i = 0; i < array.Length; i++){array[i] = this.ReadChar();}return array;}public string[] ReadStrArray(int n){var array = new string[n];for (int i = 0; i < array.Length; i++){array[i] = this.ReadStr();}return array;}public Tuple<long, long>[] ReadTupLongArray(int n, int add = 0){var array = new Tuple<long, long>[n];for (int i = 0; i < n; i++){array[i] = this.ReadTupLong(add);}return array;}public Tuple<int, int>[] ReadTupArray(int n, int add = 0){var array = new Tuple<int, int>[n];for (int i = 0; i < n; i++){array[i] = this.ReadTup(add);}return array;}public Tuple<int, int, int>[] ReadTup3Array(int n, int add = 0){var array = new Tuple<int, int, int>[n];for (int i = 0; i < n; i++){array[i] = this.ReadTup3(add);}return array;}public Tuple<int, int, int, int>[] ReadTup4Array(int n, int add = 0){var array = new Tuple<int, int, int, int>[n];for (int i = 0; i < n; i++){array[i] = this.ReadTup4(add);}return array;}}