using System;
using System.Diagnostics;

namespace NumericPerfTestCSharp {
    class Program {
        static void Main() {
            var collection = new int[100000000];

            Benchmark(() => SumForEach(collection), "SumForEach");
            Benchmark(() => SumFor(collection), "SumFor");
            
        }
        static long SumForEach(int[] collection) {
            long sum = 0;
            foreach (var i in collection) {
                sum += i;
            }
            return sum;
        }

        static long SumFor(int[] collection) {
            long sum = 0;
            for (int i = 0; i < collection.Length; ++i) {
                sum += collection[i];
            }
            return sum;
        }

        static void Benchmark<T>(Func<T> func, string message) {
            // warm-up call
            func();

            var sw = new Stopwatch();
            for (int i = 0; i < 5; ++i) {
                sw.Start();
                var res = func();
                sw.Stop();
                // Write result just to prevent the compiler from optimising away the method call
                Console.Write(res);
            }
            Console.Write('\n');
            Console.WriteLine(message + " : {0} ms", sw.ElapsedMilliseconds);
        }
    }
}