using System;
using System.Text;
using System.Linq;
using System.Collections.Generic;
using System.Security.Cryptography;
using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Attributes.Columns;
using BenchmarkDotNet.Attributes.Exporters;
using BenchmarkDotNet.Attributes.Jobs;
using BenchmarkDotNet.Running;

namespace MyBenchmarks
{
    [CoreJob]
    [RankColumn]
    public class StringBenchmarks
    {
        private string[] data;

        [Params(1, 2, 3, 4, 5, 10, 40, 160)]
        public int N;

        [GlobalSetup]
        public void Setup()
        {
            data = Enumerable.Range(0, N).Select(_ => Guid.NewGuid().ToString()).ToArray();
        }

        [Benchmark]
        public string WithStupidConcat()
        {
            var s = "";
            foreach (var x in data)
            {
                s += x;
            }
            return s;
        }

        [Benchmark]
        public string WithStringConcat() => String.Concat(data);

        [Benchmark]
        public string WithStringBuilder()
        {
            var s = new StringBuilder();
            foreach (var x in data)
            {
                s.Append(x);
            }
            return s.ToString();
        }
    }

    public class Program
    {
        public static void Main(string[] args)
        {
            var summary = BenchmarkRunner.Run<StringBenchmarks>();
        }
    }
}