Find the word with most anagrams in a given sentence

Given a string S in the form of a sentence, the task is to find the word from the text with maximum number of its anagrams present in the given sentence.
Example:

Input: S = “please be silent and listen to what the professor says”
Output: silent
Explanation:
Only the word “silent” has an anagram(listen) present in the sentence.
Input: S = “cat is not a dog and sword has no words when government creates act so what is tac”
Output: cat
Explanation:
The word “cat” has two anagrams (“act”, “tac”) present in the sentence.
The word “words” has an anagram (“sword”) present in the sentence.
Hence, the word with the maximum anagrams is “cat”.

Approach:
Following observations need to be made to solve the program:

Property of Prime Numbers: The product of any combination of prime numbers generates an unique number which cannot be obtained by any other combination of prime numbers.

Follow the steps below to solve the problem:

Assign each alphabet with a distinct prime number.
For each word in the given string, calculate the product of prime numbers assigned to the characters of that word and store it in a HashMap.
Calculate the product of prime numbers assigned to the characters of a word and store it in a HashMap.
Find the product with maximum frequency in the HashMap and print one of the corresponding anagrams as the answer.

Below is the implementation of the above approach:

Java

// Java Program to find the word 
// with most anagrams in a sentence 
import java.util.*; 
  
class GFG { 
  
    // Function to find the word with 
    // maximum number of anagrams 
    private static String largestAnagramGrp( 
        String arr[]) 
    { 
        // Primes assigned to 26 alphabets 
        int prime[] 
            = { 2, 3, 5, 7, 11, 13, 17, 
                19, 23, 29, 31, 37, 41, 
                43, 47, 53, 59, 61, 67, 71, 
                73, 79, 83, 89, 97, 101 }; 
  
        int max = -1; 
        long maxpdt = -1; 
  
        // Stores the product and 
        // word mappings 
        HashMap<Long, String> W 
            = new HashMap<>(); 
  
        // Stores the frequencies 
        // of products 
        HashMap<Long, Integer> P 
            = new HashMap<>(); 
  
        for (String temp : arr) { 
            char c[] = temp.toCharArray(); 
            long pdt = 1; 
  
            // Calculate the product of 
            // primes assigned 
            for (char t : c) { 
                pdt *= prime[t - 'a']; 
            } 
  
            // If product already exists 
            if (P.containsKey(pdt)) { 
                P.put(pdt, P.get(pdt) + 1); 
            } 
  
            // Otherwise 
            else { 
                W.put(pdt, temp); 
                P.put(pdt, 1); 
            } 
        } 
  
        // Fetch the most frequent product 
        for (Map.Entry<Long, Integer> 
                 e : P.entrySet()) { 
            if (max < e.getValue()) { 
                max = e.getValue(); 
                maxpdt = e.getKey(); 
            } 
        } 
  
        // Return a string 
        // with that product 
        return W.get(maxpdt); 
    } 
  
    // Driver Code 
    public static void main(String args[]) 
    { 
        String S = "please be silent and listen"
                   + " to what the professor says "; 
        String arr[] = S.split("[ ]+"); 
        System.out.println(largestAnagramGrp(arr)); 
    } 
} 

C#

// C# program to find the word 
// with most anagrams in a sentence 
using System; 
using System.Collections.Generic; 
  
class GFG{ 
  
// Function to find the word with 
// maximum number of anagrams 
private static String largestAnagramGrp(String []arr) 
{ 
      
    // Primes assigned to 26 alphabets 
    int []prime = { 2, 3, 5, 7, 11, 13, 17, 
                    19, 23, 29, 31, 37, 41, 
                    43, 47, 53, 59, 61, 67, 71, 
                    73, 79, 83, 89, 97, 101 }; 
  
    int max = -1; 
    long maxpdt = -1; 
  
    // Stores the product and 
    // word mappings 
    Dictionary<long,  
               String> W = new Dictionary<long, 
                                          String>(); 
  
    // Stores the frequencies 
    // of products 
    Dictionary<long,  
               int> P = new Dictionary<long,  
                                       int>(); 
                                         
    foreach(String temp in arr)  
    { 
        char []c = temp.ToCharArray(); 
        long pdt = 1; 
  
        // Calculate the product of 
        // primes assigned 
        foreach(char t in c) 
        { 
            pdt *= prime[t - 'a']; 
        } 
  
        // If product already exists 
        if (P.ContainsKey(pdt)) 
        { 
            P[pdt] = P[pdt] + 1; 
        } 
  
        // Otherwise 
        else 
        { 
            W.Add(pdt, temp); 
            P.Add(pdt, 1); 
        } 
    } 
  
    // Fetch the most frequent product 
    foreach(KeyValuePair<long, int> e in P) 
    { 
        if (max < e.Value) 
        { 
            max = e.Value; 
            maxpdt = e.Key; 
        } 
    } 
  
    // Return a string 
    // with that product 
    return W[maxpdt]; 
} 
  
// Driver Code 
public static void Main(String []args) 
{ 
    String S = "please be silent and listen" + 
               " to what the professor says "; 
                 
    String []arr = S.Split(' '); 
      
    Console.WriteLine(largestAnagramGrp(arr)); 
} 
} 
  
// This code is contributed by sapnasingh4991 

Output:

silent

Time Complexity: O(N), N is the length of the string excluding the blankspaces.
Auxiliary Space: O(N)

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My Personal Notes

Java

C#

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