結果
問題 | No.1507 Road Blocked |
ユーザー |
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提出日時 | 2021-05-14 22:32:08 |
言語 | C#(csc) (csc 3.9.0) |
結果 |
AC
|
実行時間 | 415 ms / 2,000 ms |
コード長 | 5,500 bytes |
コンパイル時間 | 1,987 ms |
コンパイル使用メモリ | 114,360 KB |
実行使用メモリ | 58,748 KB |
最終ジャッジ日時 | 2024-10-02 02:19:24 |
合計ジャッジ時間 | 14,638 ms |
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 30 |
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.Generic;using System.Collections;using System.Collections.Specialized;using System.Linq;using System.Text;using System.IO;using System.Reflection;using static System.Math;using System.Numerics;using System.Threading;using System.Runtime.CompilerServices;static class Program{const int mod=998244353;static List<int>[] li;static bool[] b;static int[] g;static void Main(){Sc sc=new Sc();var s=sc.Ia;int n=s[0],m=n-1;li=new List<int>[n+1];b=new bool[n+1];g=new int[n+1];for(int i=1;i<=n;i++){li[i]=new List<int>();}var h=new int[m][];for(int i=0;i<m;i++){h[i]=sc.Ia;li[h[i][0]].Add(h[i][1]);li[h[i][1]].Add(h[i][0]);}int r=1;Fu(r);var al=new Alca(li,true,r);Mint ans=0;for(int i = 0;i<m;i++) {long c=0,d=0;if(al.Di(r,h[i][0])<al.Di(r,h[i][1])){c=n-g[h[i][1]];d=g[h[i][1]];}else{c=g[h[i][0]];d=n-g[h[i][0]];}Mint p=(c*(c-1)/2+d*(d-1)/2)%mod;Mint q=(c*(c-1)/2+d*(d-1)/2+c*d)%mod;ans+=p/q;}Console.WriteLine("{0}",ans/(n-1));}static void Fu(int a){b[a]=true;g[a]=1;for(int i=0;i<li[a].Count;i++){if(!b[li[a][i]]){Fu(li[a][i]);g[a]+=g[li[a][i]];}}}}public struct Mint{const int mod=998244353;private long d;public Mint(long d){this.d=d;}public static implicit operator Mint(long d){return new Mint(d%mod);}public static explicit operator long(Mint d){return d.d;}public override string ToString(){return d.ToString();}public static Mint operator+(Mint a,long b){a.d=(a.d+b)%mod;return a;}public static Mint operator+(Mint a,Mint b){a.d=(a.d+b.d)%mod;return a;}public static Mint operator-(Mint a,long b){a.d=(mod+a.d-b)%mod;return a;}public static Mint operator-(Mint a,Mint b){a.d=(mod+a.d-b.d)%mod;return a;}public static Mint operator*(Mint a,long b){a.d=(a.d*b)%mod;return a;}public static Mint operator*(Mint a,Mint b){a.d=(a.d*b.d)%mod;return a;}public static Mint operator/(Mint a,long b){a.d=(a.d*Mi(b))%mod;return a;}public static Mint operator/(Mint a,Mint b){a.d=(a.d*Mi(b.d))%mod;return a;}public static bool operator==(Mint a,long b){return (long)a==b;}public static bool operator!=(Mint a,long b){return (long)a!=b;}public override bool Equals(object obj){return false;}public override int GetHashCode(){return 0;}public static long Mi(long a){a=(a+mod)%mod;long b=mod,u=1,v=0;while(b>0){long t=a/b;a-=t*b;(a,b)=(b,a);u-=t*v;(u,v)=(v,u);}u%=mod;if(u<0){u+=mod;}return u%mod;}}public class Alca{private List<int>[] li;private readonly int[] at,l;public readonly int[] ix,de;private readonly int[][] g;private int f=0;public Alca(List<int>[] li,bool bo,int r){int n=li.Length,z=(n<<1)-3,m=0;this.li=li;at=new int[z];ix=new int[n];de=new int[n];if(bo){Fu1(r,1);}else{for(int i = 1;i<n;i++) {if(de[i]==0){Fu1(i,1);f++;}}}m=(int)Log(z,2)+1;g=new int[m][];g[0]=new int[z];l=new int[z+1];for(int i=0;i<z;i++){g[0][i]=i;l[i+1]=l[i>>1]+1;}for(int i=1,k=1;i<m;i++,k<<=1){int p=z+1-(k<<1);g[i]=new int[p];for(int j=0;j<p;j++){g[i][j]=de[at[g[i-1][j]]]<de[at[g[i-1][j+k]]]?g[i-1][j]:g[i-1][j+k];}}}public int Lca(int a,int b){return Get(ix[a],ix[b]);}public int Di(int a,int b){int p=Get(ix[a],ix[b]);return p!=0?de[a]+de[b]-(de[p]<<1):-1;}private int Get(int a,int b){if(a>b){(a,b)=(b,a);}int p=l[b-a];return at[de[at[g[p][a]]]<de[at[g[p][b+1-(1<<p)]]]?g[p][a]:g[p][b+1-(1<<p)]];}private void Fu1(int a,int g){at[f]=a;de[a]=g;ix[a]=f;f++;for(int i=0;i<li[a].Count;i++){if(de[li[a][i]]==0){Fu1(li[a][i],g+1);at[f]=a;f++;}}}}public class Sc{public int I{get{return int.Parse(Console.ReadLine());}}public long L{get{return long.Parse(Console.ReadLine());}}public double D{get{return double.Parse(Console.ReadLine());}}public string S{get{return Console.ReadLine();}}public int[] Ia{get{return Array.ConvertAll(Console.ReadLine().Split(),int.Parse);}}public long[] La{get{return Array.ConvertAll(Console.ReadLine().Split(),long.Parse);}}public double[] Da{get{return Array.ConvertAll(Console.ReadLine().Split(),double.Parse);}}public string[] Sa{get{return Console.ReadLine().Split();}}public object[] Oa{get{return Console.ReadLine().Split();}}public int[] Ia2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),int.Parse);}}public int[] Ia3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),int.Parse);}public long[] La2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),long.Parse);}}public long[] La3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),long.Parse);}public double[] Da2{get{return Array.ConvertAll(("0 "+Console.ReadLine()+" 0").Split(),double.Parse);}}public double[] Da3(string a,string b){return Array.ConvertAll((a+Console.ReadLine()+b).Split(),double.Parse);}public T[] Arr<T>(int n,Func<T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f();}return a;}public T[] Arr<T>(int n,Func<int,T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i);}return a;}public T[] Arr<T>(int n,Func<string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(Console.ReadLine().Split());}return a;}public T[] Arr<T>(int n,Func<int,string[],T> f){var a=new T[n];for(int i=0;i<n;i++){a[i]=f(i,Console.ReadLine().Split());}return a;}}