Add GoodSuffixRule sample code

Author: jcazevedo

src/main/java/com/packt/datastructuresandalg/lesson5/goodsuffixrule/GoodSuffixRule.java

@@ -0,0 +1,58 @@
+package com.packt.datastructuresandalg.lesson5.goodsuffixrule;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class GoodSuffixRule {
+    public List<Integer> match(String P, String T) {
+        int n = T.length();
+        int m = P.length();
+        int i = m, j = m + 1;
+        int[] f = new int[m + 1];
+        int[] s = new int[m + 1];
+        f[i] = j;
+        while (i > 0) {
+            while (j <= m && P.charAt(i - 1) != P.charAt(j - 1)) {
+                if (s[j] == 0)
+                    s[j] = j - i;
+                j = f[j];
+            }
+            i--; j--;
+            f[i] = j;
+        }
+
+        j = f[0];
+        for (i = 0; i <= m; i++) {
+            if (s[i] == 0)
+                s[i] = j;
+            if (i == j)
+                j = f[j];
+        }
+
+        List<Integer> shifts = new ArrayList<>();
+        int skip;
+        for (i = 0; i < n - m + 1; i += skip) {
+            boolean hasMatch = true;
+            skip = 0;
+            for (j = m - 1; j >= 0; j--) {
+                if (P.charAt(j) != T.charAt(i + j)) {
+                    skip = s[j + 1];
+                    hasMatch = false;
+                    break;
+                }
+            }
+            if (hasMatch) {
+                shifts.add(i);
+                skip = s[0];
+            }
+        }
+        return shifts;
+    }
+
+    public static void main(String [] args) {
+        GoodSuffixRule gsr = new GoodSuffixRule();
+        List<Integer> matches = gsr.match("rabrabracad", "abacadabrabracabracadabrabrabracad");
+        for (Integer i : matches)
+            System.out.println(i);
+    }
+}