Replace consecutive duplicate occurrences with the count of repetitions using C++

By ARYA CHANDRAKAR

A program to do basic string compression. For a character that is consecutively repeated more than once, replace consecutive duplicate occurrences with the count of repetitions. In C++ language.

Example:-

If a string has 'x' repeated 5 times, replace this "xxxxx" with "x5".

The string is compressed only when the repeated character count is more than 1.


Code:-

   #include <bits/stdc++.h>
   using namespace std;

string getCompressedString(string &input) {
   
   if (input.length() == 0)
       return "";

       
       // Variables to iterate the string and keep the count of the current character.

       int startIndex = 0;

       int endIndex = 0;

       // Resultant string.

       string compressedString = "";

       // Iterate all the characters of the string.

       while (startIndex < input.length()) {

       while ((endIndex < input.length()) && (input[endIndex] == input[startIndex])) 
           {
               endIndex += 1;
           }
           int totalCharCount = endIndex - startIndex;

           // If count is greater than 1, then append count to the string, else only character.

           if (totalCharCount != 1)
            {
               compressedString += input[startIndex];
               compressedString += (char)(totalCharCount + '0');
           }
           else
            {
               compressedString += input[startIndex];
            }
           startIndex = endIndex;
       }
       return compressedString;
   }

   int main() {
       int size = 1e6;
       string str;
       cin >> str;
       str = getCompressedString(str);
       cout << str << endl;
   }

  

 

Input

aaabbcddeeeee

Output

a3b2cd2e5