diff --git a/src/main/java/com/thealgorithms/strings/HorspoolSearch.java b/src/main/java/com/thealgorithms/strings/HorspoolSearch.java index cc35dbbbf..9ac0d50ca 100644 --- a/src/main/java/com/thealgorithms/strings/HorspoolSearch.java +++ b/src/main/java/com/thealgorithms/strings/HorspoolSearch.java @@ -100,6 +100,10 @@ public class HorspoolSearch { shiftValues = calcShiftValues(pattern); // build the bad symbol table comparisons = 0; // reset comparisons + if (pattern.length() == 0) { // return failure, if pattern empty + return -1; + } + int textIndex = pattern.length() - 1; // align pattern with text start and get index of the last character // while pattern is not out of text bounds diff --git a/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java b/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java new file mode 100644 index 000000000..9240ac8a5 --- /dev/null +++ b/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java @@ -0,0 +1,88 @@ +package com.thealgorithms.strings; + +import org.junit.jupiter.api.Test; + +import static org.junit.jupiter.api.Assertions.*; + +class HorspoolSearchTest { + + @Test + void testFindFirstMatch() { + int index = HorspoolSearch.findFirst("World", "Hello World"); + assertEquals(6, index); + } + + @Test + void testFindFirstNotMatch() { + int index = HorspoolSearch.findFirst("hell", "Hello World"); + assertEquals(-1, index); + } + + @Test + void testFindFirstPatternLongerText() { + int index = HorspoolSearch.findFirst("Hello World!!!", "Hello World"); + assertEquals(-1, index); + } + + @Test + void testFindFirstPatternEmpty() { + int index = HorspoolSearch.findFirst("", "Hello World"); + assertEquals(-1, index); + } + + @Test + void testFindFirstTextEmpty() { + int index = HorspoolSearch.findFirst("Hello", ""); + assertEquals(-1, index); + } + + @Test + void testFindFirstPatternAndTextEmpty() { + int index = HorspoolSearch.findFirst("", ""); + assertEquals(-1, index); + } + + @Test + void testFindFirstSpecialCharacter() { + int index = HorspoolSearch.findFirst("$3**", "Hello $3**$ World"); + assertEquals(6, index); + } + + @Test + void testFindFirstInsensitiveMatch() { + int index = HorspoolSearch.findFirstInsensitive("hello", "Hello World"); + assertEquals(0, index); + } + + @Test + void testFindFirstInsensitiveNotMatch() { + int index = HorspoolSearch.findFirstInsensitive("helo", "Hello World"); + assertEquals(-1, index); + } + + @Test + void testGetLastComparisons() { + HorspoolSearch.findFirst("World", "Hello World"); + int lastSearchNumber = HorspoolSearch.getLastComparisons(); + assertEquals(7, lastSearchNumber); + } + + @Test + void testGetLastComparisonsNotMatch() { + HorspoolSearch.findFirst("Word", "Hello World"); + int lastSearchNumber = HorspoolSearch.getLastComparisons(); + assertEquals(3, lastSearchNumber); + } + + @Test + void testFindFirstPatternNull() { + assertThrows(NullPointerException.class, + () -> HorspoolSearch.findFirst(null, "Hello World")); + } + + @Test + void testFindFirstTextNull() { + assertThrows(NullPointerException.class, + () -> HorspoolSearch.findFirst("Hello", null)); + } +} \ No newline at end of file