codeforces-template/Codeforces.Test/IOTester.cs

namespace Codeforces.Test
{
	public class IOTester
	{
		private static StringReader? stdIn;
		private static StringWriter? stdOut;

		public static void Start()
		{
			stdOut = new StringWriter();
			Console.SetOut(stdOut);
		}

		public static void SetInput(params string[] lines)
		{
			string input = string.Join(Environment.NewLine, lines);
			stdIn = new StringReader(input);
			Console.SetIn(stdIn);
		}

		public static IEnumerable<string> GetOutputLines()
		{
			return stdOut?.ToString()
				.Split(Environment.NewLine)
				.SkipLast(1)
				?? Enumerable.Empty<string>();
		}
	}
}