public class MiniString {
       private char[] chars;

       public MiniString(char[] theChars) {
       	      chars = new char[theChars.length];
	      //have to copy one at a time to avoid the aliasing issues
	      for (int i=0; i < theChars.length; i++) {
	      	  chars[i] = theChars[i];
	      }
       }

       public MiniString(String word) {
       	      chars = new char[theChars.length];
	      for (int i=0; i < word.length(); i++) {
	      	  chars[i] = word.charAt(i);
	      }
       }

       public int length() {
       	      return this.chars.length;
       }

       public char charAt(int i) {
       	      return this.chars[i];
       }

       public String toString() {
       	      String builder = "";
	      for (int i=0; i < chars.length; i++) {
	      	  builder = builder + chars[i];
	      }
	      
	      return builder;
       }

       //this method duplicates the char array in a way to avoid aliasing
       public char[] toCharArray() {
       	      char[] duplicate = new char[chars.length];
	      for (int i=0; i < duplicate.length; i++) {
	      	  duplicate[i] = chars[i];
	      }

	      return duplicate;
       }

       public boolean equals(MiniString other) {
       	      if (other == null) {
	      	 return false;
	      }

	      if (this.chars.length != other.chars.length) {
	      	 return false;
	      }

	      for (int i=0; i < this.chars.length; i++) {
	      	  if (this.chars[i] != other.chars[i]) {
		     return false;
		  }
	      }

	      return true;
       }

       public int compareTo(MiniString other) {
       	      for (int i=0; i < other.chars.length && i < this.chars.length; i++) {
	      	  if (other.chars[i] < this.chars[i]) {
		     return -1;
		  }

		  if (other.chars[i] > this.chars[i] ) {
		     return 1;
		  }
	      }

	      if (others.length() < this.length()) {
	      	 return -1;
	      }

	      if (this.length() < others.length()) {
	      	 return 1;
	      }

	      return 0;
       }

       public MiniString concatenate(MiniString addition) {
       	      char[] newLetters = new char[this.chars.length + addition.length()];
	      for (int i=0; i < this.chars.length; i++) {
	      	  newLetters[i] = this.chars[i];
	      }

	      for (int i=0; i < addition.length(); i++) {
	      	  newLetters[i + this.chars.length] = addition.charAt(i);
	      }

	      return new MiniString(newLetters);
       }

       public MiniString substring(int start, int end) {
       	      char[] newLetters = new char[end - start];
	      for (int i=0; i < newLetters.length; i++) {
	      	  newLetters[i] = this.chars[i + start];
	      }

	      return new MiniString(newLetters);
       }

       public MiniString substring(int start) {
       	      return this.substring(start, this.chars.length);
       }

       public MiniString(char oldChar, char newChar) {
       	      char[] replaced = new char[chars.length];
	      for (int i=0; i < replaced.length; i++) {
	      	  if (this.chars[i] == oldChar) {
		     replaced[i] = newChar;
		  }
		  else
		  {
		     replaced[i] = chars[i];
		  }
	      }

	      return new MiniString(replaced);
       }

       public int indexOf(char c, int start) {
       	      for (int i=start; i < chars.length; i++) {
	      	  if (this.chars[i] == c) {
		     return i;
		  }
	      }
	      
	      return -1;
       }

       public int indexOf(char c) {
       	      return indexOf(c, 0);
       }
}