c#第二章课后第三题

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.Threading.Tasks;namespace ConsoleApplication2{    class Program    {        static void Main(string[] args)        {            Console.WriteLine("请输入行数");            int hang=int.Parse(Console.ReadLine());            for (int i = 1; i <= hang;i++)            {                for (int j = 1; j <= i;j++ )                {                    Console.Write(i);                }                Console.WriteLine();            }            Console.ReadLine();                                }    }}