Given a string of lowercase characters, the task is to print the string in a manner such that a character comes first in string displays first with all its occurrences in string.
Examples:
Input : str = "geeksforgeeks" Output: ggeeeekkssfor Explanation: In the given string 'g' comes first and occurs 2 times so it is printed first Then 'e' comes in this string and 4 times so it gets printed. Similarly remaining string is printed. Input : str = "occurrence" output : occcurreen Input : str = "cdab" Output : cdab
This problem is a string version of following problem for array of integers.
Group multiple occurrence of array elements ordered by first occurrences
Since given strings have only 26 possible characters, it is easier to implement for strings.
Implementation:
1- Count the occurrence of all the characters in given string using an array of size 26.
2- Then start traversing the string. Print every character its count times.
C++
// C++ program to print all occurrences of every character // together. # include<bits/stdc++.h> using namespace std; // Since only lower case characters are there const int MAX_CHAR = 26; // Function to print the string void printGrouped(string str) { int n = str.length(); // Initialize counts of all characters as 0 int count[MAX_CHAR] = {0}; // Count occurrences of all characters in string for (int i = 0 ; i < n ; i++) count[str[i]-'a']++; // Starts traversing the string for (int i = 0; i < n ; i++) { // Print the character till its count in // hash array while (count[str[i]-'a']--) cout << str[i]; // Make this character's count value as 0. count[str[i]-'a'] = 0; } } // Driver code int main() { string str = "geeksforgeeks"; printGrouped(str); return 0; } |
Java
// Java program to print all occurrences of every character // together. class Test { // Since only lower case characters are there static final int MAX_CHAR = 26; // Method to print the string static void printGrouped(String str) { int n = str.length(); // Initialize counts of all characters as 0 int count[] = new int[MAX_CHAR]; // Count occurrences of all characters in string for (int i = 0 ; i < n ; i++) count[str.charAt(i)-'a']++; // Starts traversing the string for (int i = 0; i < n ; i++) { // Print the character till its count in // hash array while (count[str.charAt(i)-'a']!=0){ System.out.print(str.charAt(i)); count[str.charAt(i)-'a']--; } // Make this character's count value as 0. count[str.charAt(i)-'a'] = 0; } } // Driver method public static void main(String args[]) { String str = new String("geeksforgeeks"); printGrouped(str); } } |
Python3
# Python3 program to print all occurrences # of every character together. # Since only lower case characters are there MAX_CHAR = 26 # Function to print the string def printGrouped(string): n = len(string) # Initialize counts of all characters as 0 count = [0] * MAX_CHAR # Count occurrences of all characters in string for i in range(n): count[ord(string[i]) - ord("a")] += 1 # Starts traversing the string for i in range(n): # Print the character till its count in # hash array while count[ord(string[i]) - ord("a")]: print(string[i], end = "") count[ord(string[i]) - ord("a")] -= 1 # Make this character's count value as 0. count[ord(string[i]) - ord("a")] = 0 # Driver code if __name__ == "__main__": string = "geeksforgeeks" printGrouped(string) # This code is contributed by # sanjeev2552 |
C#
// C# program to print all // occurrences of every // character together. using System; class GFG { // Since only lower case // characters are there static int MAX_CHAR = 26; // Method to print // the string static void printGrouped(String str) { int n = str.Length; // Initialize counts of // all characters as 0 int []count = new int[MAX_CHAR]; // Count occurrences of // all characters in string for (int i = 0 ; i < n ; i++) count[str[i] - 'a']++; // Starts traversing // the string for (int i = 0; i < n ; i++) { // Print the character // till its count in // hash array while (count[str[i] - 'a'] != 0) { Console.Write(str[i]); count[str[i] - 'a']--; } // Make this character's // count value as 0. count[str[i] - 'a'] = 0; } } // Driver code public static void Main() { string str = "geeksforgeeks"; printGrouped(str); } } // This code is contributed by Sam007 |
Output:
ggeeeekkssfor
This article is contributed by Sahil Chhabra. 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.
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