Submission #1608964


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, M;
    void solve()
    {
        N = cin.nextint;
        M = cin.nextint;
        input(M);
        var flag = find_negative_loop(N, M, 0);
        WriteLine(flag ? "inf" : $"{-D[N - 1]}");
    }

    struct Edge
    {
        public int from, to; public long cost;
        public Edge(int from, int to, long cost)
        {
            this.from = from;
            this.to = to;
            this.cost = cost;
        }
    }
    Edge[] G;
    long[] D;
    const long inf = long.MaxValue / 3;
    void input(int m)
    {
        G = new Edge[m];
        for (int i = 0; i < m; i++)
        {
            int a = cin.nextint - 1;
            int b = cin.nextint - 1;
            long c = -cin.nextlong;
            G[i] = new Edge(a, b, c);
        }
    }
    bool find_negative_loop(int n, int m, int s)
    {
        D = Enumerable.Repeat(inf, n).ToArray();
        D[s] = 0;
        for (int i = 0; i < n; i++)
        {
            foreach (var e in G)
            {
                if (D[e.to] > D[e.from] + e.cost)
                {
                    D[e.to] = D[e.from] + e.cost;

                    // n回目にも更新があるなら負の閉路が存在する
                    if (i == n - 1 && e.to == n - 1) return true;
                }
            }
        }
        return false;
    }
}

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

Submission Time
Task D - Score Attack
User claw88
Language C# (Mono 4.6.2.0)
Score 400
Code Size 3008 Byte
Status AC
Exec Time 35 ms
Memory 13360 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 400 / 400
Status
AC × 3
AC × 30
Set Name Test Cases
Sample sample_01.txt, sample_02.txt, sample_03.txt
All sample_01.txt, sample_02.txt, sample_03.txt, subtask_1_1.txt, subtask_1_10.txt, subtask_1_11.txt, subtask_1_12.txt, subtask_1_13.txt, subtask_1_14.txt, subtask_1_15.txt, subtask_1_16.txt, subtask_1_17.txt, subtask_1_18.txt, subtask_1_19.txt, subtask_1_2.txt, subtask_1_20.txt, subtask_1_21.txt, subtask_1_22.txt, subtask_1_23.txt, subtask_1_24.txt, subtask_1_25.txt, subtask_1_26.txt, subtask_1_27.txt, subtask_1_3.txt, subtask_1_4.txt, subtask_1_5.txt, subtask_1_6.txt, subtask_1_7.txt, subtask_1_8.txt, subtask_1_9.txt
Case Name Status Exec Time Memory
sample_01.txt AC 24 ms 11220 KB
sample_02.txt AC 23 ms 13268 KB
sample_03.txt AC 23 ms 9172 KB
subtask_1_1.txt AC 24 ms 9172 KB
subtask_1_10.txt AC 23 ms 9172 KB
subtask_1_11.txt AC 24 ms 11220 KB
subtask_1_12.txt AC 30 ms 11304 KB
subtask_1_13.txt AC 24 ms 9272 KB
subtask_1_14.txt AC 30 ms 11304 KB
subtask_1_15.txt AC 35 ms 11288 KB
subtask_1_16.txt AC 24 ms 11220 KB
subtask_1_17.txt AC 24 ms 11220 KB
subtask_1_18.txt AC 28 ms 11308 KB
subtask_1_19.txt AC 30 ms 9256 KB
subtask_1_2.txt AC 28 ms 11304 KB
subtask_1_20.txt AC 24 ms 9272 KB
subtask_1_21.txt AC 28 ms 13352 KB
subtask_1_22.txt AC 32 ms 9240 KB
subtask_1_23.txt AC 24 ms 11220 KB
subtask_1_24.txt AC 29 ms 11304 KB
subtask_1_25.txt AC 25 ms 11328 KB
subtask_1_26.txt AC 29 ms 13352 KB
subtask_1_27.txt AC 30 ms 11304 KB
subtask_1_3.txt AC 27 ms 13360 KB
subtask_1_4.txt AC 28 ms 11304 KB
subtask_1_5.txt AC 25 ms 9140 KB
subtask_1_6.txt AC 29 ms 9256 KB
subtask_1_7.txt AC 28 ms 13360 KB
subtask_1_8.txt AC 28 ms 9256 KB
subtask_1_9.txt AC 23 ms 9300 KB