Print all valid words that are possible using Characters of Array
Given a dictionary and a character array, print all valid words that are possible using characters from the array.
Examples:
Input : Dict - {"go","bat","me","eat","goal",
"boy", "run"}
arr[] = {'e','o','b', 'a','m','g', 'l'}
Output : go, me, goal.
Asked In : Microsoft Interview
The idea is to use Trie data structure to store dictionary, then search words in Trie using characters of given array.
- Create an empty Trie and insert all words of given dictionary into the Trie.
- After that, we have pick only those characters in ‘Arr[]’ which are a child of the root of Trie.
- To quickly find whether a character is present in array or not, we create a hash of character arrays.
Below is the implementation of above idea
C++
// C++ program to print all valid words that // are possible using character of array #include<bits/stdc++.h> using namespace std; // Converts key current character into index // use only 'a' through 'z' #define char_int(c) ((int)c - (int)'a') //converts current integer into character #define int_to_char(c) ((char)c + (char)'a') // Alphabet size #define SIZE (26) // trie Node struct TrieNode { TrieNode *Child[SIZE]; // isLeaf is true if the node represents // end of a word bool leaf; }; // Returns new trie node (initialized to NULLs) TrieNode *getNode() { TrieNode * newNode = new TrieNode; newNode->leaf = false; for (int i =0 ; i< SIZE ; i++) newNode->Child[i] = NULL; return newNode; } // If not present, inserts key into trie // If the key is prefix of trie node, just // marks leaf node void insert(TrieNode *root, char *Key) { int n = strlen(Key); TrieNode * pChild = root; for (int i=0; i<n; i++) { int index = char_int(Key[i]); if (pChild->Child[index] == NULL) pChild->Child[index] = getNode(); pChild = pChild->Child[index]; } // make last node as leaf node pChild->leaf = true; } // A recursive function to print all possible valid // words present in array void searchWord(TrieNode *root, bool Hash[], string str) { // if we found word in trie / dictionary if (root->leaf == true) cout << str << endl ; // traverse all child's of current root for (int K =0; K < SIZE; K++) { if (Hash[K] == true && root->Child[K] != NULL ) { // add current character char c = int_to_char(K); // Recursively search reaming character of word // in trie searchWord(root->Child[K], Hash, str + c); } } } // Prints all words present in dictionary. void PrintAllWords(char Arr[], TrieNode *root, int n) { // create a 'has' array that will store all present // character in Arr[] bool Hash[SIZE]; for (int i = 0 ; i < n; i++) Hash[char_int(Arr[i])] = true; // tempary node TrieNode *pChild = root ; // string to hold output words string str = ""; // Traverse all matrix elements. There are only 26 // character possible in char array for (int i = 0 ; i < SIZE ; i++) { // we start searching for word in dictionary // if we found a character which is child // of Trie root if (Hash[i] == true && pChild->Child[i] ) { str = str+(char)int_to_char(i); searchWord(pChild->Child[i], Hash, str); str = ""; } } } //Driver program to test above function int main() { // Let the given dictionary be following char Dict[][20] = {"go", "bat", "me", "eat", "goal", "boy", "run"} ; // Root Node of Trie TrieNode *root = getNode(); // insert all words of dictionary into trie int n = sizeof(Dict)/sizeof(Dict[0]); for (int i=0; i<n; i++) insert(root, Dict[i]); char arr[] = {'e', 'o', 'b', 'a', 'm', 'g', 'l'} ; int N = sizeof(arr)/sizeof(arr[0]); PrintAllWords(arr, root, N); return 0; } |
chevron_right
filter_none
Java
// Java program to print all valid words that // are possible using character of array public class SearchDict_charArray { // Alphabet size static final int SIZE = 26; // trie Node static class TrieNode { TrieNode[] Child = new TrieNode[SIZE]; // isLeaf is true if the node represents // end of a word boolean leaf; // Constructor public TrieNode() { leaf = false; for (int i =0 ; i< SIZE ; i++) Child[i] = null; } } // If not present, inserts key into trie // If the key is prefix of trie node, just // marks leaf node static void insert(TrieNode root, String Key) { int n = Key.length(); TrieNode pChild = root; for (int i=0; i<n; i++) { int index = Key.charAt(i) - 'a'; if (pChild.Child[index] == null) pChild.Child[index] = new TrieNode(); pChild = pChild.Child[index]; } // make last node as leaf node pChild.leaf = true; } // A recursive function to print all possible valid // words present in array static void searchWord(TrieNode root, boolean Hash[], String str) { // if we found word in trie / dictionary if (root.leaf == true) System.out.println(str); // traverse all child's of current root for (int K =0; K < SIZE; K++) { if (Hash[K] == true && root.Child[K] != null ) { // add current character char c = (char) (K + 'a'); // Recursively search reaming character // of word in trie searchWord(root.Child[K], Hash, str + c); } } } // Prints all words present in dictionary. static void PrintAllWords(char Arr[], TrieNode root, int n) { // create a 'has' array that will store all // present character in Arr[] boolean[] Hash = new boolean[SIZE]; for (int i = 0 ; i < n; i++) Hash[Arr[i] - 'a'] = true; // tempary node TrieNode pChild = root ; // string to hold output words String str = ""; // Traverse all matrix elements. There are only // 26 character possible in char array for (int i = 0 ; i < SIZE ; i++) { // we start searching for word in dictionary // if we found a character which is child // of Trie root if (Hash[i] == true && pChild.Child[i] != null ) { str = str+(char)(i + 'a'); searchWord(pChild.Child[i], Hash, str); str = ""; } } } //Driver program to test above function public static void main(String args[]) { // Let the given dictionary be following String Dict[] = {"go", "bat", "me", "eat", "goal", "boy", "run"} ; // Root Node of Trie TrieNode root = new TrieNode(); // insert all words of dictionary into trie int n = Dict.length; for (int i=0; i<n; i++) insert(root, Dict[i]); char arr[] = {'e', 'o', 'b', 'a', 'm', 'g', 'l'} ; int N = arr.length; PrintAllWords(arr, root, N); } } // This code is contributed by Sumit Ghosh |
chevron_right
filter_none
C#
// C# program to print all valid words that // are possible using character of array using System; public class SearchDict_charArray { // Alphabet size static readonly int SIZE = 26; // trie Node public class TrieNode { public TrieNode[] Child = new TrieNode[SIZE]; // isLeaf is true if the node represents // end of a word public Boolean leaf; // Constructor public TrieNode() { leaf = false; for (int i =0 ; i< SIZE ; i++) Child[i] = null; } } // If not present, inserts key into trie // If the key is prefix of trie node, just // marks leaf node static void insert(TrieNode root, String Key) { int n = Key.Length; TrieNode pChild = root; for (int i = 0; i < n; i++) { int index = Key[i] - 'a'; if (pChild.Child[index] == null) pChild.Child[index] = new TrieNode(); pChild = pChild.Child[index]; } // make last node as leaf node pChild.leaf = true; } // A recursive function to print all possible valid // words present in array static void searchWord(TrieNode root, Boolean []Hash, String str) { // if we found word in trie / dictionary if (root.leaf == true) Console.WriteLine(str); // traverse all child's of current root for (int K = 0; K < SIZE; K++) { if (Hash[K] == true && root.Child[K] != null ) { // add current character char c = (char) (K + 'a'); // Recursively search reaming character // of word in trie searchWord(root.Child[K], Hash, str + c); } } } // Prints all words present in dictionary. static void PrintAllWords(char []Arr, TrieNode root, int n) { // create a 'has' array that will store all // present character in Arr[] Boolean[] Hash = new Boolean[SIZE]; for (int i = 0 ; i < n; i++) Hash[Arr[i] - 'a'] = true; // tempary node TrieNode pChild = root ; // string to hold output words String str = ""; // Traverse all matrix elements. There are only // 26 character possible in char array for (int i = 0 ; i < SIZE ; i++) { // we start searching for word in dictionary // if we found a character which is child // of Trie root if (Hash[i] == true && pChild.Child[i] != null ) { str = str+(char)(i + 'a'); searchWord(pChild.Child[i], Hash, str); str = ""; } } } // Driver code public static void Main(String []args) { // Let the given dictionary be following String []Dict = {"go", "bat", "me", "eat", "goal", "boy", "run"} ; // Root Node of Trie TrieNode root = new TrieNode(); // insert all words of dictionary into trie int n = Dict.Length; for (int i = 0; i < n; i++) insert(root, Dict[i]); char []arr = {'e', 'o', 'b', 'a', 'm', 'g', 'l'} ; int N = arr.Length; PrintAllWords(arr, root, N); } } /* This code is contributed by PrinciRaj1992 */ |
chevron_right
filter_none
Output:
go goal me
This article is contributed by Nishant Singh . If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
