Print the string by ignoring alternate occurrences of any character

Given a string of both uppercase and lowercase alphabets, the task is to print the string with alternate occurrences of any character dropped(including space and consider upper and lowercase as same).

Examples:

Input : It is a long day Dear.
Output : It sa longdy ear.
Print first I and then ignore next i.
Similarly print first space then 
ignore next space.


Input : Geeks for geeks
Output : Geks fore

Asked in: Microsoft

Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.

As we have to print characters in alternate manner, so start traversing the string and perform following two steps:-

Increment the count of occurrence of current character in a hash table.
Check if the count becomes odd, then print the current character, else not.

C/C++

// C++ program to print the string in given pattern 
#include <bits/stdc++.h> 
using namespace std; 
  
// Function to print the string 
void printStringAlternate(string str) 
{ 
    unordered_map<char, int> occ; 
  
    // Start traversing the string 
    for (int i = 0; i < str.length(); i++) { 
  
        // Convert uppercase to lowercase 
        char temp = tolower(str[i]); 
  
        // Increment occurrence count 
        occ[temp]++; 
  
        // If count is odd then print the character 
        if (occ[temp] & 1) 
            cout << str[i]; 
    } 
  
    cout << endl; 
} 
  
// Drivers code 
int main() 
{ 
    string str = "Geeks for geeks"; 
    string str2 = "It is a long day Dear"; 
  
    printStringAlternate(str); 
    printStringAlternate(str2); 
  
    return 0; 
} 

Java

// Java program to print the string in given pattern 
import java.io.*; 
  
class GFG  
{ 
    // Function to print the string 
    static void printStringAlternate(String str) 
    { 
        int[] occ = new int[122]; 
          
        // Convert uppercase to lowercase 
        String s = str.toLowerCase(); 
   
        // Start traversing the string 
        for (int i = 0; i < str.length(); i++)  
        { 
              
            char temp = s.charAt(i); 
   
            // Increment occurrence count 
            occ[temp]++; 
   
            // If count is odd then print the character 
            if (occ[temp]%2 != 0) 
                System.out.print(str.charAt(i)); 
        } 
        System.out.println(); 
    } 
      
    // driver program 
    public static void main (String[] args)  
    { 
        String str1 = "Geeks for geeks"; 
        String str2 = "It is a long day Dear"; 
        printStringAlternate(str1); 
        printStringAlternate(str2); 
    } 
} 
  
// Contributed by Pramod Kumar 

Python3

# Python3 program to print the string  
# in given pattern  
  
# Function to print the string  
def printStringAlternate(string):  
  
    occ = {}  
  
    # Start traversing the string  
    for i in range(0, len(string)):  
  
        # Convert uppercase to lowercase  
        temp = string[i].lower() 
  
        # Increment occurrence count  
        occ[temp] = occ.get(temp, 0) + 1
  
        # If count is odd then print the character  
        if occ[temp] & 1: 
            print(string[i], end = "")  
  
    print() 
  
# Driver code  
if __name__ == "__main__": 
  
    string = "Geeks for geeks"
    string2 = "It is a long day Dear"
  
    printStringAlternate(string)  
    printStringAlternate(string2)  
  
# This code is contributed by Rituraj Jain 

C#

// C# program to print the  
// string in given pattern 
using System; 
          
public class GFG { 
      
    // Function to print the string 
    static void printStringAlternate(String str)  
    { 
        int[] occ = new int[122]; 
          
        // Convert uppercase to lowercase 
        string s = str.ToLower(); 
  
  
        // Start traversing the string 
        for (int i = 0; i < str.Length; i++)  
        { 
              
            char temp = s[i]; 
  
            // Increment occurrence count 
            occ[temp]++; 
  
            // If count is odd then print 
            // the character 
            if (occ[temp] % 2 != 0) 
                Console.Write(str[i]); 
        } 
        Console.WriteLine(); 
    } 
      
    // Driver Code 
    public static void Main ()  
    { 
        string str1 = "Geeks for geeks"; 
        string str2 = "It is a long day Dear"; 
        printStringAlternate(str1); 
        printStringAlternate(str2); 
    } 
} 
  
// This code is contributed by Sam007. 

PHP

<?php 
// PHP program to print the string 
// in given pattern 
  
// Function to print the string 
function printStringAlternate($str) 
{ 
    $occ = array(); 
      
    // Convert uppercase to lowercase 
    $s = strtolower($str); 
  
    // Start traversing the string 
    for ($i = 0; $i < strlen($str); $i++)  
    { 
          
        $temp = $s[$i]; 
  
        // Increment occurrence count 
        $occ[($temp)]++; 
  
        // If count is odd  
        // then print the character 
        if ($occ[$temp] % 2 != 0) 
            echo($str[$i]); 
    } 
    echo "\n"; 
} 
  
// Driver Code 
$str1 = "Geeks for geeks"; 
$str2 = "It is a long day Dear"; 
printStringAlternate($str1); 
printStringAlternate($str2); 
  
// This code is contributed by Code_Mech. 
?> 

Output:

Geks fore
It sa longdy ear

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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My Personal Notes

Recommended: Please solve it on “PRACTICE ” first, before moving on to the solution.

C/C++

Java

Python3

C#

PHP

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