catalan number practice - first writing has a bug (index out of range, negative index value), the line 45 is added to solve the index out of range error

catalan number practice.cs

using System;

class Solution
{
    public static int NumOfPathsToDest(int n)
    {      
        // your code goes here
        if(n < 0)
        {
          return -1; 
        }
    
        if(n == 0)
        {
          return 1; 
        }
    
        // n > 0 
        int Size = n ; 
      
        var path = new int[Size][]; 
        for(int row = 0; row < Size; row++)
        {
          path[row] = new int[Size]; // 4          
        }
      
        for(int row = 0; row < Size; row++)
        {
          for(int col = 0; col < Size; col++)  // not col <= row, 5, 1 
          {
            var isZero = row == 0; 
            if(isZero)
            {
              path[0][col] = 1;               
            }            
            
            var blackArea = row > col; 
            if(blackArea)
            {
              path[row][col] = 0; 
            }
            else
            {         
              // row - 1 >= 0, col - 1 >= 0
              var checking = (row - 1) >= 0 && (col - 1) >= 0; 
              if(checking)
              {
                path[row][col] = path[row - 1][col] + path[row][col - 1]; // col - 1 >= 0, row - 1 >= 0
              }
            }            
          }
        }
        
        return path[n - 1][n - 1]; 
    }

    static void Main(string[] args)
    {
          Console.WriteLine(NumOfPathsToDest(4)); 
    }
}