Rabin-Karp string search done!

Fun exercise. Some takeaways:
1. Smallest test case is easy to walk through and verify the logic,
indexing, and such is correct;
2. Persist, don't give up, take it step by step, and you'll reach the goal!

Hooray!

2 files changed, 53 insertions, 0 deletions

diff --git a/src/test/HashChainsTest.java b/src/test/HashChainsTest.java
index 9a7f192..57255fc 100644
--- a/src/test/HashChainsTest.java
+++ b/src/test/HashChainsTest.java
@@ -15,5 +15,6 @@ class HashChainsTest {
         hc.bucketCount = 3;
         assertEquals(1, hc.hashFunc("add"));
         assertEquals(1, hc.hashFunc("help"));
+        assertEquals(2, hc.hashFunc("del"));
     }
 }
\ No newline at end of file
diff --git a/src/test/HashSubstringTest.java b/src/test/HashSubstringTest.java
new file mode 100644
index 0000000..854b329
--- /dev/null
+++ b/src/test/HashSubstringTest.java
@@ -0,0 +1,52 @@
+import org.junit.jupiter.api.Test;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class HashSubstringTest {
+    @Test
+    void test() {
+        HashSubstring.Data data = new HashSubstring.Data("aba", "abacaba");
+        assertEquals(2, HashSubstring.getOccurrences(data).size());
+        assertEquals(0, HashSubstring.getOccurrences(data).get(0));
+        assertEquals(4, HashSubstring.getOccurrences(data).get(1));
+
+        List<Integer> postions = HashSubstring.rabinKarp("a", "ab");
+        assertEquals(1, postions.size());
+        assertEquals(0, postions.get(0));
+
+        postions = HashSubstring.rabinKarp("a", "ba");
+        assertEquals(1, postions.size());
+        assertEquals(1, postions.get(0));
+
+        postions = HashSubstring.rabinKarp("aba", "abacaba");
+        assertEquals(2, postions.size());
+        assertEquals(0, postions.get(0));
+        assertEquals(4, postions.get(1));
+    }
+
+    @Test
+    void test1() {
+        HashSubstring.Data data = new HashSubstring.Data("Test", "testTesttesT");
+        assertEquals(1, HashSubstring.getOccurrences(data).size());
+        assertEquals(4, HashSubstring.getOccurrences(data).get(0));
+        List<Integer> postions = HashSubstring.rabinKarp("Test", "testTesttesT");
+        assertEquals(1, postions.size());
+        assertEquals(4, postions.get(0));
+    }
+
+    @Test
+    void test2() {
+        HashSubstring.Data data = new HashSubstring.Data("aaaaa", "baaaaaaa");
+        assertEquals(3, HashSubstring.getOccurrences(data).size());
+        assertEquals(1, HashSubstring.getOccurrences(data).get(0));
+        assertEquals(2, HashSubstring.getOccurrences(data).get(1));
+        assertEquals(3, HashSubstring.getOccurrences(data).get(2));
+        List<Integer> positions = HashSubstring.rabinKarp("aaaaa", "baaaaaaa");
+        assertEquals(3, positions.size());
+        assertEquals(1, positions.get(0));
+        assertEquals(2, positions.get(1));
+        assertEquals(3, positions.get(2));
+    }
+}
\ No newline at end of file