Adding WildCardMatcher code

Author: RicardoRibeiroRodrigues

Algorithms/Strings/PatternMatching/WildCardMatcher.cs

@@ -0,0 +1,59 @@
+using System;
+
+namespace Algorithms.Strings.PatternMatching;
+
+public static class WildCardMatcher
+{
+    public static bool MatchPattern(string inputString, string pattern)
+    {
+        if (pattern.Length > 0 & pattern[0] == '*')
+        {
+            throw new ArgumentException("Pattern cannot start with *");
+        }
+
+        var inputLength = inputString.Length + 1;
+        var patternLength = pattern.Length + 1;
+
+        // DP 2d matrix, where dp[i, j] is true if the first i characters in the input string match the first j characters in the pattern
+        // This DP is initialized to all falses, as it is the default value for a boolean.
+        var dp = new bool[inputLength, patternLength];
+
+        // Empty string and empty pattern are a match
+        dp[0, 0] = true;
+
+        // Since the empty string can only match a pattern that has a * in it, we need to initialize the first row of the DP matrix
+        for (var j = 1; j < patternLength; j++)
+        {
+            if (pattern[j - 1] == '*')
+            {
+                dp[0, j] = dp[0, j - 2];
+            }
+        }
+
+        // Now using bottom-up approach to find for all remaining lenghts of input and pattern
+        for (var i = 1; i < inputLength; i++)
+        {
+            for (var j = 1; j < patternLength; j++)
+            {
+                // If the characters match or the pattern has a ., then the result is the same as the previous characters
+                if (inputString[i - 1] == pattern[j - 1] || pattern[j - 1] == '.')
+                {
+                    dp[i, j] = dp[i - 1, j - 1];
+                }
+                else if (pattern[j - 1] == '*')
+                {
+                    if (dp[i, j - 2])
+                    {
+                        dp[i, j] = true;
+                    }
+                    else if (inputString[i - 1] == pattern[j - 2] || pattern[j - 2] == '.')
+                    {
+                        dp[i, j] = dp[i - 1, j];
+                    }
+                }
+            }
+        }
+
+        return dp[inputLength - 1, patternLength - 1];
+    }
+}