Submission #1101735


Source Code Expand

using System;
using System.Linq;
using System.Collections.Generic;
using Debug = System.Diagnostics.Debug;
using StringBuilder = System.Text.StringBuilder;
using System.Numerics;
using Point = System.Numerics.Complex;
using Number = System.Int64;
namespace Program
{
    public class Solver
    {
        public void Solve()
        {
            var n = sc.Integer();
            var a = sc.Integer();
            var b = sc.Integer();
            var c = sc.Integer();
            if (b % 2 != 0) { IO.Printer.Out.WriteLine(0); return; }
            const long MOD = (long)1e9 + 7;
            var C = Enumerate(n + 50, x => new long[n + 50]);
            C[0][0] = 1;
            for (int i = 0; i <= n; i++)
                for (int j = 0; j <= n; j++)
                {
                    C[i + 1][j] = (C[i + 1][j] + C[i][j]) % MOD;
                    C[i + 1][j + 1] = (C[i + 1][j + 1] + C[i][j]) % MOD;
                }
            long ans = 0;
            for (int i = 0; i <= a; i++)
                for (int j = 0; 3 * j <= c; j++)
                {
                    if (c - 3 * j < a - i) continue;
                    var x = i;
                    var y = j;
                    var z = a - i;
                    var rem = c - 3 * j - z;
                    long p = C[x + y][x];
                    p = (p * C[x + y + z][z]) % MOD;
                    if (rem > 0)
                    {
                        if (b > 0)
                            p = (p * C[rem + b / 2 - 1][rem]) % MOD;
                        else p = 0;

                    }
                    p = (p * C[x + y + z + b / 2][b / 2]) % MOD;
                    ans = (ans + p) % MOD;

                }
            IO.Printer.Out.WriteLine(ans);
        }
        public IO.StreamScanner sc = new IO.StreamScanner(Console.OpenStandardInput());
        static T[] Enumerate<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; }
        static public void Swap<T>(ref T a, ref T b) { var tmp = a; a = b; b = tmp; }
    }
}

#region main
static class Ex
{
    static public string AsString(this IEnumerable<char> ie) { return new string(System.Linq.Enumerable.ToArray(ie)); }
    static public string AsJoinedString<T>(this IEnumerable<T> ie, string st = " ") { return string.Join(st, ie); }
    static public void Main()
    {
        var solver = new Program.Solver();
        solver.Solve();
        Program.IO.Printer.Out.Flush();
    }
}
#endregion
#region Ex
namespace Program.IO
{
    using System.IO;
    using System.Text;
    using System.Globalization;
    public class Printer: StreamWriter
    {
        static Printer() { Out = new Printer(Console.OpenStandardOutput()) { AutoFlush = false }; }
        public static Printer Out { get; set; }
        public override IFormatProvider FormatProvider { get { return CultureInfo.InvariantCulture; } }
        public Printer(System.IO.Stream stream) : base(stream, new UTF8Encoding(false, true)) { }
        public Printer(System.IO.Stream stream, Encoding encoding) : base(stream, encoding) { }
        public void Write<T>(string format, T[] source) { base.Write(format, source.OfType<object>().ToArray()); }
        public void WriteLine<T>(string format, T[] source) { base.WriteLine(format, source.OfType<object>().ToArray()); }
    }
    public class StreamScanner
    {
        public StreamScanner(Stream stream) { str = stream; }
        public readonly Stream str;
        private readonly byte[] buf = new byte[1024];
        private int len, ptr;
        public bool isEof = false;
        public bool IsEndOfStream { get { return isEof; } }
        private byte read()
        {
            if (isEof) return 0;
            if (ptr >= len) { ptr = 0; if ((len = str.Read(buf, 0, 1024)) <= 0) { isEof = true; return 0; } }
            return buf[ptr++];
        }
        public char Char() { byte b = 0; do b = read(); while ((b < 33 || 126 < b) && !isEof); return (char)b; }

        public string Scan()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b >= 33 && b <= 126; b = (char)read())
                sb.Append(b);
            return sb.ToString();
        }
        public string ScanLine()
        {
            var sb = new StringBuilder();
            for (var b = Char(); b != '\n'; b = (char)read())
                if (b == 0) break;
                else if (b != '\r') sb.Append(b);
            return sb.ToString();
        }
        public long Long()
        {
            if (isEof) return long.MinValue;
            long ret = 0; byte b = 0; var ng = false;
            do b = read();
            while (b != 0 && b != '-' && (b < '0' || '9' < b));
            if (b == 0) return long.MinValue;
            if (b == '-') { ng = true; b = read(); }
            for (; true; b = read())
            {
                if (b < '0' || '9' < b)
                    return ng ? -ret : ret;
                else ret = ret * 10 + b - '0';
            }
        }
        public int Integer() { return (isEof) ? int.MinValue : (int)Long(); }
        public double Double() { var s = Scan(); return s != "" ? double.Parse(s, CultureInfo.InvariantCulture) : double.NaN; }
        private T[] enumerate<T>(int n, Func<T> f)
        {
            var a = new T[n];
            for (int i = 0; i < n; ++i) a[i] = f();
            return a;
        }

        public char[] Char(int n) { return enumerate(n, Char); }
        public string[] Scan(int n) { return enumerate(n, Scan); }
        public double[] Double(int n) { return enumerate(n, Double); }
        public int[] Integer(int n) { return enumerate(n, Integer); }
        public long[] Long(int n) { return enumerate(n, Long); }
    }
}
#endregion

Submission Info

Submission Time
Task J - 123 Pairs
User camypaper
Language C# (Mono 4.6.2.0)
Score 1500
Code Size 5912 Byte
Status AC
Exec Time 1398 ms
Memory 206376 KB

Judge Result

Set Name Sample All
Score / Max Score 0 / 0 1500 / 1500
Status
AC × 2
AC × 52
Set Name Test Cases
Sample example0.txt, example1.txt
All 000.txt, 001.txt, 002.txt, 003.txt, 004.txt, 005.txt, 006.txt, 007.txt, 008.txt, 009.txt, 010.txt, 011.txt, 012.txt, 013.txt, 014.txt, 015.txt, 016.txt, 017.txt, 018.txt, 019.txt, 020.txt, 021.txt, 022.txt, 023.txt, 024.txt, 025.txt, 026.txt, 027.txt, 028.txt, 029.txt, 030.txt, 031.txt, 032.txt, 033.txt, 034.txt, 035.txt, 036.txt, 037.txt, 038.txt, 039.txt, 040.txt, 041.txt, 042.txt, 043.txt, 044.txt, 045.txt, 046.txt, 047.txt, 048.txt, 049.txt, example0.txt, example1.txt
Case Name Status Exec Time Memory
000.txt AC 1317 ms 206368 KB
001.txt AC 1249 ms 206376 KB
002.txt AC 1249 ms 206376 KB
003.txt AC 1249 ms 206376 KB
004.txt AC 1252 ms 206376 KB
005.txt AC 1251 ms 206376 KB
006.txt AC 1250 ms 206376 KB
007.txt AC 1249 ms 206376 KB
008.txt AC 1252 ms 206376 KB
009.txt AC 1250 ms 206376 KB
010.txt AC 1238 ms 205352 KB
011.txt AC 1219 ms 203304 KB
012.txt AC 1235 ms 204968 KB
013.txt AC 46 ms 12120 KB
014.txt AC 47 ms 11992 KB
015.txt AC 1225 ms 193448 KB
016.txt AC 156 ms 28888 KB
017.txt AC 476 ms 75072 KB
018.txt AC 132 ms 20824 KB
019.txt AC 614 ms 98872 KB
020.txt AC 677 ms 119864 KB
021.txt AC 1322 ms 203808 KB
022.txt AC 969 ms 162608 KB
023.txt AC 1270 ms 206376 KB
024.txt AC 1356 ms 206376 KB
025.txt AC 1267 ms 206376 KB
026.txt AC 1306 ms 206376 KB
027.txt AC 1345 ms 206376 KB
028.txt AC 1282 ms 206376 KB
029.txt AC 1291 ms 206376 KB
030.txt AC 1337 ms 206376 KB
031.txt AC 1352 ms 206376 KB
032.txt AC 1257 ms 206376 KB
033.txt AC 20 ms 2648 KB
034.txt AC 626 ms 100152 KB
035.txt AC 1036 ms 165416 KB
036.txt AC 582 ms 98232 KB
037.txt AC 21 ms 2904 KB
038.txt AC 1398 ms 206376 KB
039.txt AC 20 ms 2648 KB
040.txt AC 20 ms 2648 KB
041.txt AC 1283 ms 206376 KB
042.txt AC 1249 ms 206376 KB
043.txt AC 21 ms 2776 KB
044.txt AC 21 ms 2776 KB
045.txt AC 21 ms 2776 KB
046.txt AC 21 ms 2776 KB
047.txt AC 21 ms 2776 KB
048.txt AC 21 ms 2776 KB
049.txt AC 21 ms 2776 KB
example0.txt AC 21 ms 2776 KB
example1.txt AC 35 ms 6104 KB