Submission #1608919

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Source Code Expand

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
using static System.Console;
using Pair = System.Collections.Generic.KeyValuePair<int, int>;
//using System.Numerics;
using static System.Math;

class Program
{
    static void Main()
    {
        //SetOut(new StreamWriter(OpenStandardOutput()) { AutoFlush = false });
        new Program().solve();
        Out.Flush();
    }
    Scanner cin = new Scanner();
    readonly int[] dd = { 0, 1, 0, -1, 0 };
    readonly int mod = 1000000007;
    readonly string alfa = "abcdefghijklmnopqrstuvwxyz";
    readonly string ALFA = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    int N;
    List<int>[] G;
    bool[] B;
    void solve()
    {
        N = cin.nextint;
        G = Enumerable.Range(0, N).Select(i => new List<int>()).ToArray();
        for (int i = 0; i < N - 1; i++)
        {
            int x = cin.nextint - 1;
            int y = cin.nextint - 1;
            G[x].Add(y);
            G[y].Add(x);
        }
        B = new bool[N];
        int ret = calc(0);
        WriteLine(ret == 0 ? "Bob" : "Alice");
    }
    int calc(int u)
    {
        B[u] = true;

        int xor = 0;
        int item = 0;
        foreach (var v in G[u])
        {
            if (B[v]) continue;
            xor ^= calc(v);
            item++;
        }
        if (item == 1) xor++;
        return xor;
    }

}

class Scanner
{
    string[] s; int i;
    char[] cs = new char[] { ' ' };
    public Scanner() { s = new string[0]; i = 0; }
    public string[] scan { get { return ReadLine().Split(); } }
    public int[] scanint { get { return Array.ConvertAll(scan, int.Parse); } }
    public long[] scanlong { get { return Array.ConvertAll(scan, long.Parse); } }
    public double[] scandouble { get { return Array.ConvertAll(scan, double.Parse); } }
    public string next
    {
        get
        {
            if (i < s.Length) return s[i++];
            string st = ReadLine();
            while (st == "") st = ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            i = 0;
            return next;
        }
    }
    public int nextint { get { return int.Parse(next); } }
    public long nextlong { get { return long.Parse(next); } }
    public double nextdouble { get { return double.Parse(next); } }
}

Submission Info

Judge Result