c# 输出两个三角形（菱形）

namespace ConsoleApplication5
{
class Program
{
static void Main(string[] args)
{
Console.WriteLine("Type in a int:");
int input = Convert.ToInt32(Console.ReadLine()) ;
// Console.WriteLine(input);
if (input < 0)
Console.WriteLine("input a -int!");
else
{
if (input == 0)
Console.WriteLine("input 0");
else
{
for (int i = 0; i < input; i++)
{
for (int j = 0; j <= input-i; j++)
Console.Write(" ");
for(int k=0;k<2*i+1;k++)
Console.Write("*");
Console.WriteLine();

}
for (int i = 1; i < input; i++)
{
for (int j = 0; j <= i+1; j++)
Console.Write(" ");
for (int k = 0; k < 2*input-2 * i - 1; k++)
Console.Write("*");
Console.WriteLine();

}




}
}
Console.Read();
}
}
}