Compress string aabbbccc to a2b3c3

 package collectionPrograms;

public class CompressString {

public static void main(String[] args) {

// TODO Auto-generated method stub

    String input = "aaabbbbbccdddd";  

    

    

    char inChar[] = input.toCharArray();

    String output = "";

    int i;

    for(i=0;i<input.length();i++) {

    int count = 1;

   while(i+1<input.length() && inChar[i] == inChar[i+1]) {

        count+=1;

        i+=1;

      }

      output+=inChar[i]+String.valueOf(count);

    }

    System.out.println(output);

  }

}