Leetcode 10 - code review, and then write in C# code

Leetcode10_regularExpression_practice.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace LeetcodeDynamicProgramming_Practice
{
    /// <summary>
    /// code review on Dec. 21, 2017
    /// Study Java code written by the blog author:
    /// https://segmentfault.com/a/1190000003904286
    /// Leetcode 10: regular expression matching 
    /// </summary>
    class Program
    {
        static void Main(string[] args)
        {
            RunTestcase2();  
        }

        public static void RunTestcase1()
        {
            var result = isMatch("aaa", "aaaa"); 
        }

        public static void RunTestcase2()
        {
            var result = isMatch("aaa", "ab*a*c*a"); 
        }

        /// <summary>        
        /// </summary>
        /// <param name="search"></param>
        /// <param name="pattern"></param>
        /// <returns></returns>
        public static bool isMatch(String search, String pattern)
        {
            var length  = search.Length;
            var pLength = pattern.Length; 

            var match = new bool[length + 1];

            match[length] = true;

            
            int pIndex = pLength -1; 
            while(pIndex >= 0)
            {
                if (pattern[pIndex] == '*')
                {
                    var previousPattern = pattern[pIndex - 1];

                    // if it is *，match from backward iteration
                    for (int matchIndex = length - 1; matchIndex >= 0; matchIndex--)
                    {                        
                        match[matchIndex] = match[matchIndex] || (match[matchIndex + 1] && (previousPattern == '.' ||
                        previousPattern == search[matchIndex]));
                    }

                    //extra decrement one, because * needs extra char to work together. .* or a* etc. 
                    pIndex -= 2;
                }
                else
                {
                    var currentPattern = pattern[pIndex];
                    
                    // foreward iteration
                    for (int searchIndex = 0; searchIndex < length; searchIndex++)
                    {                        
                        match[searchIndex] = match[searchIndex + 1] && (currentPattern == '.' || currentPattern == search[searchIndex]);
                    }

                    // 只要试过了pattern中最后一个字符，就要把match[s.length()]置为false
                    match[length] = false;

                    pIndex -= 1; 
                }
            }

            return match[0];
    }
        }
    }
}