compress String - Java Algorithm

Java examples for Algorithm:String

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Description

compress String

Demo Code


public class Main {
  public static void main(String args[]){
    String s_1 = "aabccccaaa";
    String s_2 = "abcd";
    String s_3 = "aabcccccd";
    System.out.println("Method compressString");
    System.out.println("s_1 = " + s_1);
    System.out.println(compressString(s_1));
    System.out.println("s_2 = " + s_2);
    System.out.println(compressString(s_2));
    System.out.println("s_3 = " + s_3);
    System.out.println(compressString(s_3));
  }/*from  w  ww. j  a  v  a  2s .  c om*/
  public static String compressString(String str){
    String oldStr = str;
    String newStr = "";
    int count = 1;
    
    for(int i=0; i<oldStr.length(); i++){
      if(i+1 <= str.length()-1) { // There is the next character
        if(oldStr.charAt(i) == oldStr.charAt(i+1) ) {
          count++;
          continue;
        }
        newStr = newStr + oldStr.charAt(i) + String.valueOf(count);
        count = 1; // reset for the next character
      }
      else { // We have reached the very last character
        newStr = newStr + oldStr.charAt(i) + String.valueOf(count);
        count = 1; // reset for the next character
      }
    }
    
    if (newStr.length() <= oldStr.length()) return newStr;
    else return oldStr;
  }
}

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