Improve TrieImp.java comments & enhance readability (#5526)

This commit is contained in:
Hardik Pawar
2024-10-05 15:17:52 +05:30
committed by GitHub
parent 87871efcdb
commit ce34595628
3 changed files with 156 additions and 77 deletions

View File

@ -22,7 +22,7 @@
* [WordSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/backtracking/WordSearch.java)
* bitmanipulation
* [BitSwap](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/BitSwap.java)
* [CountSetBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/CountSetBits.java)
* [CountSetBits](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/CountSetBits.java)
* [HighestSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/HighestSetBit.java)
* [IndexOfRightMostSetBit](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBit.java)
* [IsEven](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/bitmanipulation/IsEven.java)
@ -69,7 +69,7 @@
* [HexaDecimalToBinary](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/HexaDecimalToBinary.java)
* [HexaDecimalToDecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/HexaDecimalToDecimal.java)
* [HexToOct](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/HexToOct.java)
* [IntegerToEnglish] (https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java)
* [IntegerToEnglish](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IntegerToEnglish.java)
* [IntegerToRoman](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/IntegerToRoman.java)
* [OctalToBinary](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToBinary.java)
* [OctalToDecimal](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/conversions/OctalToDecimal.java)
@ -410,7 +410,7 @@
* [WordBoggle](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/misc/WordBoggle.java)
* others
* [ArrayLeftRotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/ArrayLeftRotation.java)
* [ArrayRightRotation](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ArrayRightRotation.java)
* [ArrayRightRotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/ArrayRightRotation.java)
* [BankersAlgorithm](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/BankersAlgorithm.java)
* [BFPRT](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/BFPRT.java)
* [BoyerMoore](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/BoyerMoore.java)
@ -559,8 +559,8 @@
* [CharactersSame](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/CharactersSame.java)
* [CheckAnagrams](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/CheckAnagrams.java)
* [CheckVowels](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/CheckVowels.java)
* [CountChar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/CountChar.java)
* [CountWords](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/CountWords.java)
* [CountChar](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/CountChar.java)
* [CountWords](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/CountWords.java)
* [HammingDistance](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/HammingDistance.java)
* [HorspoolSearch](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/HorspoolSearch.java)
* [Isomorphic](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Isomorphic.java)
@ -575,13 +575,13 @@
* [Pangram](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Pangram.java)
* [PermuteString](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/PermuteString.java)
* [RabinKarp](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/RabinKarp.java)
* [ReturnSubsequence](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/ReturnSubsequence.java)
* [ReturnSubsequence](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/ReturnSubsequence.java)
* [ReverseString](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/ReverseString.java)
* [ReverseStringRecursive](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/ReverseStringRecursive.java)
* [ReverseWordsInString](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/ReverseWordsInString.java)
* [Rotation](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Rotation.java)
* [StringCompression](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/StringCompression.java)
* [StringMatchFiniteAutomata](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/others/StringMatchFiniteAutomata.java)
* [StringMatchFiniteAutomata](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/StringMatchFiniteAutomata.java)
* [Upper](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/Upper.java)
* [ValidParentheses](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/ValidParentheses.java)
* [WordLadder](https://github.com/TheAlgorithms/Java/blob/master/src/main/java/com/thealgorithms/strings/WordLadder.java)
@ -606,7 +606,7 @@
* [WordSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/backtracking/WordSearchTest.java)
* bitmanipulation
* [BitSwapTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/BitSwapTest.java)
* [CountSetBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/CountSetBitsTest.java)
* [CountSetBitsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/CountSetBitsTest.java)
* [HighestSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/HighestSetBitTest.java)
* [IndexOfRightMostSetBitTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IndexOfRightMostSetBitTest.java)
* [IsEvenTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/bitmanipulation/IsEvenTest.java)
@ -621,6 +621,7 @@
* [BlowfishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/BlowfishTest.java)
* [CaesarTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/CaesarTest.java)
* [DESTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/DESTest.java)
* [HillCipherTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/HillCipherTest.java)
* [PlayfairTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PlayfairTest.java)
* [PolybiusTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/PolybiusTest.java)
* [RSATest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/ciphers/RSATest.java)
@ -639,6 +640,7 @@
* [HexaDecimalToBinaryTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/HexaDecimalToBinaryTest.java)
* [HexaDecimalToDecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/HexaDecimalToDecimalTest.java)
* [HexToOctTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/HexToOctTest.java)
* [IntegerToEnglishTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/IntegerToEnglishTest.java)
* [IntegerToRomanTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/IntegerToRomanTest.java)
* [OctalToBinaryTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToBinaryTest.java)
* [OctalToDecimalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/conversions/OctalToDecimalTest.java)
@ -727,6 +729,7 @@
* [SameTreesCheckTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SameTreesCheckTest.java)
* [SplayTreeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/SplayTreeTest.java)
* [TreeTestUtils](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TreeTestUtils.java)
* [TrieImpTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/TrieImpTest.java)
* [VerticalOrderTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/VerticalOrderTraversalTest.java)
* [ZigzagTraversalTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/datastructures/trees/ZigzagTraversalTest.java)
* divideandconquer
@ -991,8 +994,8 @@
* [CharacterSameTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CharacterSameTest.java)
* [CheckAnagramsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckAnagramsTest.java)
* [CheckVowelsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CheckVowelsTest.java)
* [CountCharTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/CountCharTest.java)
* [CountWordsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/CountWordsTest.java)
* [CountCharTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CountCharTest.java)
* [CountWordsTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/CountWordsTest.java)
* [HammingDistanceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HammingDistanceTest.java)
* [HorspoolSearchTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/HorspoolSearchTest.java)
* [IsomorphicTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/IsomorphicTest.java)
@ -1005,13 +1008,13 @@
* [PalindromeTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/PalindromeTest.java)
* [PangramTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/PangramTest.java)
* [PermuteStringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/PermuteStringTest.java)
* [ReturnSubsequenceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/ReturnSubsequenceTest.java)
* [ReturnSubsequenceTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/ReturnSubsequenceTest.java)
* [ReverseStringRecursiveTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/ReverseStringRecursiveTest.java)
* [ReverseStringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/ReverseStringTest.java)
* [ReverseWordsInStringTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/ReverseWordsInStringTest.java)
* [RotationTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/RotationTest.java)
* [StringCompressionTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/StringCompressionTest.java)
* [StringMatchFiniteAutomataTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/others/StringMatchFiniteAutomataTest.java)
* [StringMatchFiniteAutomataTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/StringMatchFiniteAutomataTest.java)
* [UpperTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/UpperTest.java)
* [ValidParenthesesTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/ValidParenthesesTest.java)
* [WordLadderTest](https://github.com/TheAlgorithms/Java/blob/master/src/test/java/com/thealgorithms/strings/WordLadderTest.java)

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@ -1,19 +1,35 @@
package com.thealgorithms.datastructures.trees;
import java.util.Scanner;
/**
* Trie Data structure implementation without any libraries
* Trie Data structure implementation without any libraries.
* <p>
* The Trie (also known as a prefix tree) is a special tree-like data structure
* that is used to store a dynamic set or associative array where the keys are
* usually strings. It is highly efficient for prefix-based searches.
* <p>
* This implementation supports basic Trie operations like insertion, search,
* and deletion.
* <p>
* Each node of the Trie represents a character and has child nodes for each
* possible character.
*
* @author <a href="https://github.com/dheeraj92">Dheeraj Kumar Barnwal</a>
*/
public class TrieImp {
/**
* Represents a Trie Node that stores a character and pointers to its children.
* Each node has an array of 26 children (one for each letter from 'a' to 'z').
*/
public class TrieNode {
TrieNode[] child;
boolean end;
/**
* Constructor to initialize a TrieNode with an empty child array
* and set end to false.
*/
public TrieNode() {
child = new TrieNode[26];
end = false;
@ -22,10 +38,22 @@ public class TrieImp {
private final TrieNode root;
/**
* Constructor to initialize the Trie.
* The root node is created but doesn't represent any character.
*/
public TrieImp() {
root = new TrieNode();
}
/**
* Inserts a word into the Trie.
* <p>
* The method traverses the Trie from the root, character by character, and adds
* nodes if necessary. It marks the last node of the word as an end node.
*
* @param word The word to be inserted into the Trie.
*/
public void insert(String word) {
TrieNode currentNode = root;
for (int i = 0; i < word.length(); i++) {
@ -39,6 +67,16 @@ public class TrieImp {
currentNode.end = true;
}
/**
* Searches for a word in the Trie.
* <p>
* This method traverses the Trie based on the input word and checks whether
* the word exists. It returns true if the word is found and its end flag is
* true.
*
* @param word The word to search in the Trie.
* @return true if the word exists in the Trie, false otherwise.
*/
public boolean search(String word) {
TrieNode currentNode = root;
for (int i = 0; i < word.length(); i++) {
@ -52,6 +90,17 @@ public class TrieImp {
return currentNode.end;
}
/**
* Deletes a word from the Trie.
* <p>
* The method traverses the Trie to find the word and marks its end flag as
* false.
* It returns true if the word was successfully deleted, false if the word
* wasn't found.
*
* @param word The word to be deleted from the Trie.
* @return true if the word was found and deleted, false if it was not found.
*/
public boolean delete(String word) {
TrieNode currentNode = root;
for (int i = 0; i < word.length(); i++) {
@ -69,75 +118,26 @@ public class TrieImp {
return false;
}
/**
* Helper method to print a string to the console.
*
* @param print The string to be printed.
*/
public static void sop(String print) {
System.out.println(print);
}
/**
* Regex to check if word contains only a-z character
* Validates if a given word contains only lowercase alphabetic characters
* (a-z).
* <p>
* The method uses a regular expression to check if the word matches the pattern
* of only lowercase letters.
*
* @param word The word to be validated.
* @return true if the word is valid (only a-z), false otherwise.
*/
public static boolean isValid(String word) {
return word.matches("^[a-z]+$");
}
public static void main(String[] args) {
TrieImp obj = new TrieImp();
String word;
@SuppressWarnings("resource") Scanner scan = new Scanner(System.in);
sop("string should contain only a-z character for all operation");
while (true) {
sop("1. Insert\n2. Search\n3. Delete\n4. Quit");
try {
int t = scan.nextInt();
switch (t) {
case 1:
word = scan.next();
if (isValid(word)) {
obj.insert(word);
} else {
sop("Invalid string: allowed only a-z");
}
break;
case 2:
word = scan.next();
boolean resS = false;
if (isValid(word)) {
resS = obj.search(word);
} else {
sop("Invalid string: allowed only a-z");
}
if (resS) {
sop("word found");
} else {
sop("word not found");
}
break;
case 3:
word = scan.next();
boolean resD = false;
if (isValid(word)) {
resD = obj.delete(word);
} else {
sop("Invalid string: allowed only a-z");
}
if (resD) {
sop("word got deleted successfully");
} else {
sop("word not found");
}
break;
case 4:
sop("Quit successfully");
System.exit(1);
break;
default:
sop("Input int from 1-4");
break;
}
} catch (Exception e) {
String badInput = scan.next();
sop("This is bad input: " + badInput);
}
}
}
}

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@ -0,0 +1,76 @@
package com.thealgorithms.datastructures.trees;
import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
public class TrieImpTest {
private TrieImp trie;
@BeforeEach
public void setUp() {
trie = new TrieImp();
}
@Test
public void testInsertAndSearchBasic() {
String word = "hello";
trie.insert(word);
assertTrue(trie.search(word), "Search should return true for an inserted word.");
}
@Test
public void testSearchNonExistentWord() {
String word = "world";
assertFalse(trie.search(word), "Search should return false for a non-existent word.");
}
@Test
public void testInsertAndSearchMultipleWords() {
String word1 = "cat";
String word2 = "car";
trie.insert(word1);
trie.insert(word2);
assertTrue(trie.search(word1), "Search should return true for an inserted word.");
assertTrue(trie.search(word2), "Search should return true for another inserted word.");
assertFalse(trie.search("dog"), "Search should return false for a word not in the Trie.");
}
@Test
public void testDeleteExistingWord() {
String word = "remove";
trie.insert(word);
assertTrue(trie.delete(word), "Delete should return true for an existing word.");
assertFalse(trie.search(word), "Search should return false after deletion.");
}
@Test
public void testDeleteNonExistentWord() {
String word = "nonexistent";
assertFalse(trie.delete(word), "Delete should return false for a non-existent word.");
}
@Test
public void testInsertAndSearchPrefix() {
String prefix = "pre";
String word = "prefix";
trie.insert(prefix);
trie.insert(word);
assertTrue(trie.search(prefix), "Search should return true for an inserted prefix.");
assertTrue(trie.search(word), "Search should return true for a word with the prefix.");
assertFalse(trie.search("pref"), "Search should return false for a prefix that is not a full word.");
}
@Test
public void testIsValidWord() {
assertTrue(TrieImp.isValid("validword"), "Word should be valid (only lowercase letters).");
assertFalse(TrieImp.isValid("InvalidWord"), "Word should be invalid (contains uppercase letters).");
assertFalse(TrieImp.isValid("123abc"), "Word should be invalid (contains numbers).");
assertFalse(TrieImp.isValid("hello!"), "Word should be invalid (contains special characters).");
assertFalse(TrieImp.isValid(""), "Empty string should be invalid.");
}
}