Print all words matching a pattern in CamelCase Notation Dictonary
Given a dictionary of words where each word follows CamelCase notation, print all words in the dictionary that match with a given pattern consisting of uppercase characters only.
CamelCase is the practice of writing compound words or phrases such that each word or abbreviation begins with a capital letter. Common examples include: “PowerPoint” and “WikiPedia”, “GeeksForGeeks”, “CodeBlocks”, etc.
Examples:
Input:
dict[] = ["Hi", "Hello", "HelloWorld", "HiTech", "HiGeek",
"HiTechWorld", "HiTechCity", "HiTechLab"]
For pattern "HT",
Output: ["HiTech", "HiTechWorld", "HiTechCity", "HiTechLab"]
For pattern "H",
Output: ["Hi", "Hello", "HelloWorld", "HiTech", "HiGeek",
"HiTechWorld", "HiTechCity", "HiTechLab"]
For pattern "HTC",
Output: ["HiTechCity"]
Input:
dict[] = ["WelcomeGeek","WelcomeToGeeksForGeeks", "GeeksForGeeks"]
For pattern "WTG",
Output: ["WelcomeToGeeksForGeeks"]
For pattern "GFG",
Output: [GeeksForGeeks]
For pattern "GG",
Output: No match found
The idea is to insert all dictionary keys into the Trie one by one. Here key refers to only Uppercase characters in original word in CamelCase notation. If we encounter the key for the first time, we need to mark the last node as leaf node and insert the complete word for that key into the vector associated with the leaf node. If we encounter a key that is already in the trie, we update the vector associated with the leaf node with current word. After all dictionary words are processed, we search for the pattern in the trie and print all words that matches the pattern.
Below is the implementation of above idea –
C++
// C++ program to print all words in the CamelCase // dictionary that matches with a given pattern #include <bits/stdc++.h> using namespace std; // Alphabet size (# of upper-Case characters) #define ALPHABET_SIZE 26 // A Trie node struct TrieNode { TrieNode* children[ALPHABET_SIZE]; // isLeaf is true if the node represents // end of a word bool isLeaf; // vector to store list of complete words // in leaf node list<string> word; }; // Returns new Trie node (initialized to NULLs) TrieNode* getNewTrieNode(void) { TrieNode* pNode = new TrieNode; if (pNode) { pNode->isLeaf = false; for (int i = 0; i < ALPHABET_SIZE; i++) pNode->children[i] = NULL; } return pNode; } // Function to insert word into the Trie void insert(TrieNode* root, string word) { int index; TrieNode* pCrawl = root; for (int level = 0; level < word.length(); level++) { // consider only uppercase characters if (islower(word[level])) continue; // get current character position index = int(word[level]) - 'A'; if (!pCrawl->children[index]) pCrawl->children[index] = getNewTrieNode(); pCrawl = pCrawl->children[index]; } // mark last node as leaf pCrawl->isLeaf = true; // push word into vector associated with leaf node (pCrawl->word).push_back(word); } // Function to print all children of Trie node root void printAllWords(TrieNode* root) { // if current node is leaf if (root->isLeaf) { for(string str : root->word) cout << str << endl; } // recurse for all children of root node for (int i = 0; i < ALPHABET_SIZE; i++) { TrieNode* child = root->children[i]; if (child) printAllWords(child); } } // search for pattern in Trie and print all words // matching that pattern bool search(TrieNode* root, string pattern) { int index; TrieNode* pCrawl = root; for (int level = 0; level < pattern.length(); level++) { index = int(pattern[level]) - 'A'; // Invalid pattern if (!pCrawl->children[index]) return false; pCrawl = pCrawl->children[index]; } // print all words matching that pattern printAllWords(pCrawl); return true; } // Main function to print all words in the CamelCase // dictionary that matches with a given pattern void findAllWords(vector<string> dict, string pattern) { // construct Trie root node TrieNode* root = getNewTrieNode(); // Construct Trie from given dict for (string word : dict) insert(root, word); // search for pattern in Trie if (!search(root, pattern)) cout << "No match found"; } // Driver function int main() { // dictionary of words where each word follows // CamelCase notation vector<string> dict = { "Hi", "Hello", "HelloWorld", "HiTech", "HiGeek", "HiTechWorld", "HiTechCity", "HiTechLab" }; // pattern consisting of uppercase characters only string pattern = "HT"; findAllWords(dict, pattern); return 0; } |
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Java
// Java program to print all words in the CamelCase // dictionary that matches with a given pattern import java.util.ArrayList; import java.util.Arrays; import java.util.List; public class CamelCase { // Alphabet size (# of upper-Case characters) static final int ALPHABET_SIZE = 26; // A Trie node static class TrieNode { TrieNode[] children = new TrieNode[ALPHABET_SIZE]; // isLeaf is true if the node represents // end of a word boolean isLeaf; // vector to store list of complete words // in leaf node List<String> word; public TrieNode() { isLeaf = false; for (int i = 0; i < ALPHABET_SIZE; i++) children[i] = null; word = new ArrayList<String>(); } } static TrieNode root; // Function to insert word into the Trie static void insert(String word) { int index; TrieNode pCrawl = root; for (int level = 0; level < word.length(); level++) { // consider only uppercase characters if (Character.isLowerCase(word.charAt(level))) continue; // get current character position index = word.charAt(level) - 'A'; if (pCrawl.children[index] == null) pCrawl.children[index] = new TrieNode(); pCrawl = pCrawl.children[index]; } // mark last node as leaf pCrawl.isLeaf = true; // push word into vector associated with leaf node (pCrawl.word).add(word); } // Function to print all children of Trie node root static void printAllWords(TrieNode root) { // if current node is leaf if (root.isLeaf) { for (String str : root.word) System.out.println(str); } // recurse for all children of root node for (int i = 0; i < ALPHABET_SIZE; i++) { TrieNode child = root.children[i]; if (child != null) printAllWords(child); } } // search for pattern in Trie and print all words // matching that pattern static boolean search(String pattern) { int index; TrieNode pCrawl = root; for (int level = 0; level < pattern.length(); level++) { index = pattern.charAt(level) - 'A'; // Invalid pattern if (pCrawl.children[index] == null) return false; pCrawl = pCrawl.children[index]; } // print all words matching that pattern printAllWords(pCrawl); return true; } // Main function to print all words in the CamelCase // dictionary that matches with a given pattern static void findAllWords(List<String> dict, String pattern) { // construct Trie root node root = new TrieNode(); // Construct Trie from given dict for (String word : dict) insert(word); // search for pattern in Trie if (!search(pattern)) System.out.println("No match found"); } // Driver function public static void main(String args[]) { // dictionary of words where each word follows // CamelCase notation List<String> dict = Arrays.asList("Hi", "Hello", "HelloWorld", "HiTech", "HiGeek", "HiTechWorld", "HiTechCity", "HiTechLab"); // pattern consisting of uppercase characters only String pattern = "HT"; findAllWords(dict, pattern); } } // This code is contributed by Sumit Ghosh |
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C#
// C# program to print all words in // the CamelCase dictionary that // matches with a given pattern using System; using System.Collections.Generic; class GFG { // Alphabet size (# of upper-Case characters) static int ALPHABET_SIZE = 26; // A Trie node public class TrieNode { public TrieNode[] children = new TrieNode[ALPHABET_SIZE]; // isLeaf is true if the node represents // end of a word public bool isLeaf; // vector to store list of complete words // in leaf node public List<String> word; public TrieNode() { isLeaf = false; for (int i = 0; i < ALPHABET_SIZE; i++) children[i] = null; word = new List<String>(); } } static TrieNode root; // Function to insert word into the Trie static void insert(String word) { int index; TrieNode pCrawl = root; for (int level = 0; level < word.Length; level++) { // consider only uppercase characters if (char.IsLower(word[level])) continue; // get current character position index = word[level] - 'A'; if (pCrawl.children[index] == null) pCrawl.children[index] = new TrieNode(); pCrawl = pCrawl.children[index]; } // mark last node as leaf pCrawl.isLeaf = true; // push word into vector // associated with leaf node (pCrawl.word).Add(word); } // Function to print all children // of Trie node root static void printAllWords(TrieNode root) { // if current node is leaf if (root.isLeaf) { foreach (String str in root.word) Console.WriteLine(str); } // recurse for all children of root node for (int i = 0; i < ALPHABET_SIZE; i++) { TrieNode child = root.children[i]; if (child != null) printAllWords(child); } } // search for pattern in Trie and // print all words matching that pattern static bool search(String pattern) { int index; TrieNode pCrawl = root; for (int level = 0; level < pattern.Length; level++) { index = pattern[level] - 'A'; // Invalid pattern if (pCrawl.children[index] == null) return false; pCrawl = pCrawl.children[index]; } // print all words matching that pattern printAllWords(pCrawl); return true; } // Main function to print all words // in the CamelCase dictionary that // matches with a given pattern static void findAllWords(List<String> dict, String pattern) { // construct Trie root node root = new TrieNode(); // Construct Trie from given dict foreach (String word in dict) insert(word); // search for pattern in Trie if (!search(pattern)) Console.WriteLine("No match found"); } // Driver Code public static void Main(String []args) { // dictionary of words where each word follows // CamelCase notation List<String> dict = new List<String>{"Hi", "Hello", "HelloWorld", "HiTech", "HiGeek", "HiTechWorld", "HiTechCity", "HiTechLab"}; // pattern consisting of // uppercase characters only String pattern = "HT"; findAllWords(dict, pattern); } } // This code is contributed by Princi Singh |
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Output:
HiTech HiTechCity HiTechLab HiTechWorld
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