Z Algorithm In C# (#2900)

Z_Algorithm/Z_Algorithm.cs

@@ -0,0 +1,121 @@
+/*
+    Z Algorithm In C#
+
+    This algorithm finds all occurrences 
+    of a pattern in a text in linear time.
+*/
+
+using System; 
+
+class PatternSearch
+{ 
+
+    /*
+        This function prints all the occurences 
+        of a pattern in a text using Z algorithm
+    */
+
+    public static void search(string text, string pattern) 
+    {
+        // Creation of Concatenated String
+        string concat = pattern + "$" + text; 
+        int l = concat.Length; 
+
+        // Construct a new temporary array
+        int[] temp = new int[l]; 
+
+        getTempArr(concat, temp); 
+
+        /* 
+            Iterate through temp array to 
+            find the matching condition
+        */
+
+        for (int i = 0; i < l; ++i) 
+        {
+            /*
+                If matched region is equal to 
+                pattern lentgh, pattern is found 
+            */
+
+            if (temp[i] == pattern.Length) 
+            {
+                Console.WriteLine("Pattern occurs at index: " + 
+                            (i - pattern.Length - 1)); 
+            } 
+        } 
+    } 
+
+    // Fills temporary array for given string str 
+    private static void getTempArr(string str, int[] temp) 
+    { 
+        int n = str.Length; 
+        int L = 0, R = 0; 
+
+        for (int i = 1; i < n; ++i) 
+        { 
+            if (i > R) 
+            { 
+                L = R = i; 
+
+                while (R < n && str[R - L] == str[R]) 
+                { 
+                    R++; 
+                } 
+                temp[i] = R - L; 
+                R--; 
+            } 
+
+            else
+            { 
+                int k = i - L; 
+
+                if (temp[k] < R - i + 1) 
+                { 
+                    temp[i] = temp[k]; 
+                } 
+
+                else
+                { 
+                    L = i; 
+
+                    while (R < n && str[R - L] == str[R]) 
+                    { 
+                        R++; 
+                    } 
+                    temp[i] = R - L; 
+                    R--; 
+                } 
+            } 
+        }
+    } 
+
+    public static void Main(string[] args) 
+    {
+        Console.WriteLine("Enter the String value: ");
+        String text = Console.ReadLine();
+
+        Console.WriteLine("Enter the Pattern to search: ");
+        String pattern = Console.ReadLine();
+        Console.WriteLine();
+
+        search(text, pattern); 
+    } 
+} 
+
+/**
+
+Enter the String value: AABACAADAAABACHGGH 
+Enter the Pattern to search: AABA
+
+Pattern occurs at index: 0 
+Pattern occurs at index: 9 
+
+---------------------------------------------------
+
+Enter the String value: THIS IS A TEST CASE 
+Enter the Pattern to search: TEST 
+
+Pattern occurs at index: 10 
+
+*/