Added Java code for Z-Algorithm (jainaman224#785)

Added Java code for Z-Algorithm

Z_Algorithm/Z_Algorithm.java

@@ -0,0 +1,74 @@
+
+public class Z_Algorithm {
+
+	static void getZarr(String str, int Z[]){
+
+	    int n = str.length(), Left = 0, Right = 0, k;
+
+	    for(int i = 1; i < n; i++)
+	    {
+	        if(i > Right)
+	        {
+	            Left = Right = i;
+
+	            while(Right < n && str.charAt(Right - Left) == str.charAt(Right))
+	                Right++;
+
+	            Z[i] = Right - Left;
+	            Right--;
+	        }
+	        else
+	        {
+	            k = i - Left;
+
+	            if(Z[k] < Right - i + 1)
+	                Z[i] = Z[k];
+	            else
+	            {
+	                Left = i;
+
+	                while(Right < n && str.charAt(Right - Left) == str.charAt(Right))
+	                    Right++;
+
+	                Z[i] = Right - Left;
+	                Right--;
+	            }
+	        }
+	    }
+	}
+
+	static void search(String text, String pattern){
+
+	    String concat = pattern + "$" + text;
+	    int size = concat.length();
+	    int Z[] = new int[size];
+
+	    getZarr(concat, Z);
+
+	    for(int i = 0; i < size; i++){
+	        if(Z[i] == pattern.length()){
+	            int index = i-pattern.length();
+	            System.out.println("Pattern found at " + index);
+	        }
+	    }
+
+
+	}
+
+	public static void main(String args[]){
+
+		String text = "namanchamanbomanamansanam";
+		String pattern = "aman";
+		search(text, pattern);
+	}
+}
+/*
+Sample Input:
+	namanchamanbomanamansanam (text)
+	aman					  (pattern)
+
+Sample Output:
+	Pattern found at 2
+	Pattern found at 8
+	Pattern found at 17
+*/