Given string str, the task is to print the characters in decreasing order of their frequency. If the frequency of two characters is the same then sort them in descending order alphabetically.
Examples:
Input: str = “geeksforgeeks”
Output:
e – 4
s – 2
k – 2
g – 2
r – 1
o – 1
f – 1
Input: str = “bbcc”
Output:
c – 2
b – 2
Approach:
- Use an unordered_map to store the frequencies of all the elements of the given string.
- Find the maximum frequency element from the map, print it with its frequency, and remove it from the map.
- Repeat the previous step while the map is not empty.
Below is the implementation of the above approach:
CPP
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to print the characters // of the given string in decreasing // order of their frequencies void printChar(string str, int len) { // To store the unordered_map< char , int > occ; for ( int i = 0; i < len; i++) occ[str[i]]++; // Map's size int size = occ.size(); unordered_map< char , int >::iterator it; // While there are elements in the map while (size--) { // Finding the maximum value // from the map unsigned currentMax = 0; char arg_max; for (it = occ.begin(); it != occ.end(); ++it) { if (it->second > currentMax || (it->second == currentMax && it->first > arg_max)) { arg_max = it->first; currentMax = it->second; } } // Print the character // alongwith its frequency cout << arg_max << " - " << currentMax << endl; // Delete the maximum value occ.erase(arg_max); } } // Driver code int main() { string str = "geeksforgeeks" ; int len = str.length(); printChar(str, len); return 0; } |
Java
// Java implementation of the approach import java.util.*; class GFG{ // Function to print the characters // of the given String in decreasing // order of their frequencies static void printChar( char []arr, int len) { // To store the HashMap<Character, Integer> occ = new HashMap<Character, Integer>(); for ( int i = 0 ; i < len; i++) if (occ.containsKey(arr[i])) { occ.put(arr[i], occ.get(arr[i]) + 1 ); } else { occ.put(arr[i], 1 ); } // Map's size int size = occ.size(); // While there are elements in the map while (size-- > 0 ) { // Finding the maximum value // from the map int currentMax = 0 ; char arg_max = 0 ; for (Map.Entry<Character, Integer> it : occ.entrySet()) { if (it.getValue() > currentMax || (it.getValue() == currentMax && it.getKey() > arg_max)) { arg_max = it.getKey(); currentMax = it.getValue(); } } // Print the character // alongwith its frequency System.out.print(arg_max + " - " + currentMax + "\n" ); // Delete the maximum value occ.remove(arg_max); } } // Driver code public static void main(String[] args) { String str = "geeksforgeeks" ; int len = str.length(); printChar(str.toCharArray(), len); } } // This code is contributed by gauravrajput1 |
C#
// C# implementation of the approach using System; using System.Collections.Generic; class GFG{ // Function to print the characters // of the given String in decreasing // order of their frequencies static void printChar( char []arr, int len) { // To store the Dictionary< char , int > occ = new Dictionary< char , int >(); for ( int i = 0; i < len; i++) if (occ.ContainsKey(arr[i])) { occ[arr[i]] = occ[arr[i]] + 1; } else { occ.Add(arr[i], 1); } // Map's size int size = occ.Count; // While there are elements in the map while (size-- > 0) { // Finding the maximum value // from the map int currentMax = 0; char arg_max = ( char )0; foreach (KeyValuePair< char , int > it in occ) { if (it.Value > currentMax || (it.Value == currentMax && it.Key > arg_max)) { arg_max = it.Key; currentMax = it.Value; } } // Print the character // alongwith its frequency Console.Write(arg_max + " - " + currentMax + "\n" ); // Delete the maximum value occ.Remove(arg_max); } } // Driver code public static void Main(String[] args) { String str = "geeksforgeeks" ; int len = str.Length; printChar(str.ToCharArray(), len); } } // This code is contributed by Princi Singh |
e - 4 s - 2 k - 2 g - 2 r - 1 o - 1 f - 1
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