Given a string str containing only lowercase English alphabets, the task is to find the sum and product of all the prime frequencies of the characters in str.
Examples:
Input: str = “neveropen”
Output: 6, 8
Only characters ‘g’, ‘k’ and ‘s’ have prime frequencies i.e. 2 + 2 + 2 = 6 and 2 * 2* 2 = 8
Character frequency g 2 e 4 k 2 s 2 f 1 o 1 r 1 Input: str = “algorithms”
Output: 0, 0
Approach:
- Traverse the string and store the frequencies of all the characters in a hash table.
- Find the frequencies which are prime using Sieve Of Eratosthenes.
- Calculate the sum and product of all of these prime frequencies and finally print the sum and product.
Below is the implementation of the above approach:
C++
// C++ program to find Sum and product of Prime// Frequencies of Characters in a String#include <bits/stdc++.h>using namespace std;// Function to create Sieve to check primesvoid SieveOfEratosthenes(bool prime[], int p_size){ // false here indicates // that it is not prime prime[0] = false; prime[1] = false; for (int p = 2; p * p <= p_size; p++) { // If prime[p] is not changed, // then it is a prime if (prime[p]) { // Update all multiples of p, // set them to non-prime for (int i = p * 2; i <= p_size; i += p) prime[i] = false; } }}// Function to find the sum of prime frequencies// of the characters of the given stringvoid sumProdOfPrimeFreq(string s){ bool prime[s.length() + 1]; memset(prime, true, sizeof(prime)); SieveOfEratosthenes(prime, s.length() + 1); int i, j; // map is used to store // character frequencies unordered_map<char, int> m; for (i = 0; i < s.length(); i++) m[s[i]]++; int sum = 0, product = 1; // Traverse the map for (auto it = m.begin(); it != m.end(); it++) { // If the frequency is prime if (prime[it->second]) { sum += it->second; product *= it->second; } } cout << "Sum = " << sum; cout << "\nProduct = " << product;}// Driver codeint main(){ string s = "neveropen"; sumProdOfPrimeFreq(s); return 0;} |
Java
// Java program to find Sum and product of Prime// Frequencies of Characters in a Stringimport java.util.*;class GFG { // Function to create Sieve to check primes static void SieveOfEratosthenes(boolean prime[], int p_size) { // false here indicates // that it is not prime prime[0] = false; prime[1] = false; for (int p = 2; p * p <= p_size; p++) { // If prime[p] is not changed, // then it is a prime if (prime[p]) { // Update all multiples of p, // set them to non-prime for (int i = p * 2; i < p_size; i += p) { prime[i] = false; } } } } // Function to find the sum of prime frequencies // of the characters of the given string static void sumProdOfPrimeFreq(char[] s) { boolean[] prime = new boolean[s.length + 1]; Arrays.fill(prime, true); SieveOfEratosthenes(prime, s.length + 1); int i, j; // map is used to store // character frequencies Map<Character, Integer> mp = new HashMap<>(); for (i = 0; i < s.length; i++) { mp.put(s[i], mp.get(s[i]) == null ? 1 : mp.get(s[i]) + 1); } int sum = 0, product = 1; // Traverse the map for (Map.Entry<Character, Integer> it : mp.entrySet()) { // If the frequency is prime if (prime[it.getValue()]) { sum += it.getValue(); product *= it.getValue(); } } System.out.print("Sum = " + sum); System.out.println("\nProduct = " + product); } // Driver code public static void main(String[] args) { String s = "neveropen"; sumProdOfPrimeFreq(s.toCharArray()); }}// This code is contributed by 29AjayKumar |
Python3
# Python3 program to find Sum and product of Prime# Frequencies of Characters in a String# Function to create Sieve to check primesdef SieveofEratosthenes(prime, p_size): # false here indicates # that it is not prime prime[0] = False prime[1] = False for p in range(2, p_size + 1): # If prime[p] is not changed, # then it is a prime if prime[p]: # Update all multiples of p, # set them to non-prime for i in range(p * 2, p_size + 1, p): prime[i] = False# Function to find the sum of prime frequencies# of the characters of the given stringdef sumProdOfPrimeFreq(s): prime = [True] * (len(s) + 2) SieveofEratosthenes(prime, len(s) + 1) i = 0 j = 0 # map is used to store # character frequencies m = dict() for i in range(len(s)): m[s[i]] = (m[s[i]] + 1) if s[i] in m else 1 s = 0 product = 1 # Traverse the map for it in m: # If the frequency is prime if prime[m[it]]: s += m[it] product *= m[it] print("Sum =", s) print("Product =", product)# Driver codeif __name__ == "__main__": s = "neveropen" sumProdOfPrimeFreq(s)# This code is contributed by# sanjeev2552 |
C#
// C# program to find Sum and product of Prime// Frequencies of Characters in a Stringusing System;using System.Collections.Generic;class GFG { // Function to create Sieve to check primes static void SieveOfEratosthenes(bool []prime, int p_size) { // false here indicates // that it is not prime prime[0] = false; prime[1] = false; for (int p = 2; p * p <= p_size; p++) { // If prime[p] is not changed, // then it is a prime if (prime[p]) { // Update all multiples of p, // set them to non-prime for (int i = p * 2; i < p_size; i += p) { prime[i] = false; } } } } // Function to find the sum of prime frequencies // of the characters of the given string static void sumProdOfPrimeFreq(char[] s) { int i; bool[] prime = new bool[s.Length + 1]; for(i=0;i<s.Length + 1;i++){ prime[i]=true; } SieveOfEratosthenes(prime, s.Length + 1); // map is used to store // character frequencies Dictionary<char, int> mp = new Dictionary<char, int>(); for (i = 0 ; i < s.Length; i++) { if(mp.ContainsKey(s[i])) { var val = mp[s[i]]; mp.Remove(s[i]); mp.Add(s[i], val + 1); } else { mp.Add(s[i], 1); } } int sum = 0, product = 1; // Traverse the map foreach(KeyValuePair<char, int> it in mp) { // If the frequency is prime if (prime[it.Value]) { sum += it.Value; product *= it.Value; } } Console.Write("Sum = " + sum); Console.WriteLine("\nProduct = " + product); } // Driver code public static void Main(String[] args) { String s = "neveropen"; sumProdOfPrimeFreq(s.ToCharArray()); }}// This code is contributed by Princi Singh |
Javascript
<script>// Javascript program to find Sum and product of Prime// Frequencies of Characters in a String// Function to create Sieve to check primesfunction SieveOfEratosthenes(prime, p_size) { // false here indicates // that it is not prime prime[0] = false; prime[1] = false; for (let p = 2; p * p <= p_size; p++) { // If prime[p] is not changed, // then it is a prime if (prime[p]) { // Update all multiples of p, // set them to non-prime for (let i = p * 2; i <= p_size; i += p) prime[i] = false; } }}// Function to find the sum of prime frequencies// of the characters of the given stringfunction sumProdOfPrimeFreq(s) { let prime = new Array(s.length + 1); prime.fill(true); SieveOfEratosthenes(prime, s.length + 1); let i, j; // map is used to store // character frequencies let m = new Map(); for (i = 0; i < s.length; i++) m.set(s[i], m.get(s[i]) == null ? 1 : m.get(s[i]) + 1); let sum = 0, product = 1; // Traverse the map for (let it of m) { console.log(m) // If the frequency is prime if (prime[it[1]]) { sum += it[1]; product *= it[1]; } } document.write("Sum = " + sum); document.write("<br>Product = " + product);}// Driver codelet s = "neveropen";sumProdOfPrimeFreq(s);// This code is contributed by gfgking</script> |
Output
Sum = 6 Product = 8
Complexity Analysis:
- Time Complexity: O(N*log(logN)), where N is the length of the given string.
- Auxiliary Space: O(N), since N extra space has been taken.
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