結果

問題 No.1507 Road Blocked
ユーザー fgwiebfaoish
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
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 3
other AC * 30
権限があれば一括ダウンロードができます
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

diff #
プレゼンテーションモードにする

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;}
}
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