Boggle (Find all possible words in a board of characters)

Given a dictionary, a method to do lookup in dictionary and a M x N board where every cell has one character. Find all possible words that can be formed by a sequence of adjacent characters. Note that we can move to any of 8 adjacent characters, but a word should not have multiple instances of same cell.

Example:

Input: dictionary[] = {"GEEKS", "FOR", "QUIZ", "GO"};
       boggle[][]   = {{'G', 'I', 'Z'},
                       {'U', 'E', 'K'},
                       {'Q', 'S', 'E'}};
      isWord(str): returns true if str is present in dictionary
                   else false.

Output:  Following words of dictionary are present
         GEEKS
         QUIZ

We strongly recommend that you click here and practice it, before moving on to the solution.

The idea is to consider every character as a starting character and find all words starting with it. All words starting from a character can be found using Depth First Traversal. We do depth first traversal starting from every cell. We keep track of visited cells to make sure that a cell is considered only once in a word.

C++

// C++ program for Boggle game 
#include <cstring> 
#include <iostream> 
using namespace std; 
  
#define M 3 
#define N 3 
  
// Let the given dictionary be following 
string dictionary[] = { "GEEKS", "FOR", "QUIZ", "GO" }; 
int n = sizeof(dictionary) / sizeof(dictionary[0]); 
  
// A given function to check if a given string is present in 
// dictionary. The implementation is naive for simplicity. As 
// per the question dictionary is given to us. 
bool isWord(string& str) 
{ 
    // Linearly search all words 
    for (int i = 0; i < n; i++) 
        if (str.compare(dictionary[i]) == 0) 
            return true; 
    return false; 
} 
  
// A recursive function to print all words present on boggle 
void findWordsUtil(char boggle[M][N], bool visited[M][N], int i, 
                   int j, string& str) 
{ 
    // Mark current cell as visited and append current character 
    // to str 
    visited[i][j] = true; 
    str = str + boggle[i][j]; 
  
    // If str is present in dictionary, then print it 
    if (isWord(str)) 
        cout << str << endl; 
  
    // Traverse 8 adjacent cells of boggle[i][j] 
    for (int row = i - 1; row <= i + 1 && row < M; row++) 
        for (int col = j - 1; col <= j + 1 && col < N; col++) 
            if (row >= 0 && col >= 0 && !visited[row][col]) 
                findWordsUtil(boggle, visited, row, col, str); 
  
    // Erase current character from string and mark visited 
    // of current cell as false 
    str.erase(str.length() - 1); 
    visited[i][j] = false; 
} 
  
// Prints all words present in dictionary. 
void findWords(char boggle[M][N]) 
{ 
    // Mark all characters as not visited 
    bool visited[M][N] = { { false } }; 
  
    // Initialize current string 
    string str = ""; 
  
    // Consider every character and look for all words 
    // starting with this character 
    for (int i = 0; i < M; i++) 
        for (int j = 0; j < N; j++) 
            findWordsUtil(boggle, visited, i, j, str); 
} 
  
// Driver program to test above function 
int main() 
{ 
    char boggle[M][N] = { { 'G', 'I', 'Z' }, 
                          { 'U', 'E', 'K' }, 
                          { 'Q', 'S', 'E' } }; 
  
    cout << "Following words of dictionary are present\n"; 
    findWords(boggle); 
    return 0; 
} 

Java

// Java program for Boggle game 
class GFG { 
    // Let the given dictionary be following 
    static final String dictionary[] = { "GEEKS", "FOR", "QUIZ", "GUQ", "EE" }; 
    static final int n = dictionary.length; 
    static final int M = 3, N = 3; 
  
    // A given function to check if a given string is present in 
    // dictionary. The implementation is naive for simplicity. As 
    // per the question dictionary is given to us. 
    static boolean isWord(String str) 
    { 
        // Linearly search all words 
        for (int i = 0; i < n; i++) 
            if (str.equals(dictionary[i])) 
                return true; 
        return false; 
    } 
  
    // A recursive function to print all words present on boggle 
    static void findWordsUtil(char boggle[][], boolean visited[][], int i, 
                              int j, String str) 
    { 
        // Mark current cell as visited and append current character 
        // to str 
        visited[i][j] = true; 
        str = str + boggle[i][j]; 
  
        // If str is present in dictionary, then print it 
        if (isWord(str)) 
            System.out.println(str); 
  
        // Traverse 8 adjacent cells of boggle[i][j] 
        for (int row = i - 1; row <= i + 1 && row < M; row++) 
            for (int col = j - 1; col <= j + 1 && col < N; col++) 
                if (row >= 0 && col >= 0 && !visited[row][col]) 
                    findWordsUtil(boggle, visited, row, col, str); 
  
        // Erase current character from string and mark visited 
        // of current cell as false 
        str = "" + str.charAt(str.length() - 1); 
        visited[i][j] = false; 
    } 
  
    // Prints all words present in dictionary. 
    static void findWords(char boggle[][]) 
    { 
        // Mark all characters as not visited 
        boolean visited[][] = new boolean[M][N]; 
  
        // Initialize current string 
        String str = ""; 
  
        // Consider every character and look for all words 
        // starting with this character 
        for (int i = 0; i < M; i++) 
            for (int j = 0; j < N; j++) 
                findWordsUtil(boggle, visited, i, j, str); 
    } 
  
    // Driver program to test above function 
    public static void main(String args[]) 
    { 
        char boggle[][] = { { 'G', 'I', 'Z' }, 
                            { 'U', 'E', 'K' }, 
                            { 'Q', 'S', 'E' } }; 
  
        System.out.println("Following words of dictionary are present"); 
        findWords(boggle); 
    } 
} 

C#

// C# program for Boggle game 
using System; 
using System.Collections.Generic; 
  
class GFG  
{ 
    // Let the given dictionary be following 
    static readonly String []dictionary = { "GEEKS", "FOR",  
                                            "QUIZ", "GUQ", "EE" }; 
    static readonly int n = dictionary.Length; 
    static readonly int M = 3, N = 3; 
  
    // A given function to check if a given string  
    // is present in dictionary. The implementation is  
    // naive for simplicity. As per the question  
    // dictionary is given to us. 
    static bool isWord(String str) 
    { 
        // Linearly search all words 
        for (int i = 0; i < n; i++) 
            if (str.Equals(dictionary[i])) 
                return true; 
        return false; 
    } 
  
    // A recursive function to print all words present on boggle 
    static void findWordsUtil(char [,]boggle, bool [,]visited,  
                              int i, int j, String str) 
    { 
        // Mark current cell as visited and 
        // append current character to str 
        visited[i, j] = true; 
        str = str + boggle[i, j]; 
  
        // If str is present in dictionary, 
        // then print it 
        if (isWord(str)) 
            Console.WriteLine(str); 
  
        // Traverse 8 adjacent cells of boggle[i,j] 
        for (int row = i - 1; row <= i + 1 && row < M; row++) 
            for (int col = j - 1; col <= j + 1 && col < N; col++) 
                if (row >= 0 && col >= 0 && !visited[row, col]) 
                    findWordsUtil(boggle, visited, row, col, str); 
  
        // Erase current character from string and  
        // mark visited of current cell as false 
        str = "" + str[str.Length - 1]; 
        visited[i, j] = false; 
    } 
  
    // Prints all words present in dictionary. 
    static void findWords(char [,]boggle) 
    { 
        // Mark all characters as not visited 
        bool [,]visited = new bool[M, N]; 
  
        // Initialize current string 
        String str = ""; 
  
        // Consider every character and look for all words 
        // starting with this character 
        for (int i = 0; i < M; i++) 
            for (int j = 0; j < N; j++) 
                findWordsUtil(boggle, visited, i, j, str); 
    } 
  
    // Driver Code 
    public static void Main(String []args) 
    { 
        char [,]boggle = { { 'G', 'I', 'Z' }, 
                           { 'U', 'E', 'K' }, 
                           { 'Q', 'S', 'E' } }; 
  
        Console.WriteLine("Following words of " +   
                          "dictionary are present"); 
        findWords(boggle); 
    } 
} 
  
// This code is contributed by PrinciRaj1992 

Note that the above solution may print the same word multiple times. For example, if we add “SEEK” to the dictionary, it is printed multiple times. To avoid this, we can use hashing to keep track of all printed words.

In below set 2, we have discussed Trie based optimized solution:
Boggle | Set 2 (Using Trie)

This article is contributed by Rishabh. Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

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My Personal Notes

Boggle (Find all possible words in a board of characters) | Set 1

We strongly recommend that you click here and practice it, before moving on to the solution.

C++

Java

C#

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