java2-home5.java

java2-home5.java

import java.util.*;

public class Answer {
	
	public String name;
	public Answer firstChild;
	public Answer nextSibling;
	
	public static <T extends Object> void p(T s){
		System.out.println(s);
	}
	
	Answer (String name, Answer firstChild, Answer nextSibling) {
		this.name = name;
		this.firstChild = firstChild;
		this.nextSibling = nextSibling;
	}
	
	Answer (String s) {
		s 		  = s.trim();
		if(s.equals("")) throw new RuntimeException();
		
		this.name = "";

		String parts[] 	 = s.split("");
		int length 	     = parts.length;
		
		for(int i=0; i<length; i++) {
			String part = parts[i].trim();
						
			if(part.equals(",")) {
				// 
				this.nextSibling = new Answer(s.substring(i, length-1));
				break;
			} 
			else if(part.equals("(")) {
				//
				int weight = -1;
				for(int j=i+1; j<length; j++) {
					if(parts[j].equals("(")) weight -= 1;
					if(parts[j].equals(")")) weight += 1;
					p(weight);
					
					if(weight==0){
						this.firstChild = new Answer(s.substring(i, j-1));
						i = j;
						break;
					}
				}
			}
			else {
				//
				this.name += part;
			}			
		}
		
	}
	   
	public static Answer parseTree (String s) {
		return new Answer(s);
	}

	public String rightParentheticRepresentation() {
		String returnString = this.name;

		if(this.firstChild!=null)	returnString = "("+this.firstChild.rightParentheticRepresentation()+")" + returnString;
		if(this.nextSibling!=null)	returnString = returnString  + "," +  this.nextSibling.rightParentheticRepresentation();
		
		return returnString;
	}
	
	public String toString() {
		String returnString = this.name;

		if(this.firstChild!=null)	returnString += "("+this.firstChild.toString()+")";
		if(this.nextSibling!=null)	returnString += ","+this.nextSibling.toString();
		
		return returnString;
	}
	
	public static void main (String[] param) {
		String s = "+(*(-(2,1),4),/(6,3))";
		Answer t = Answer.parseTree (s);
		String v = t.rightParentheticRepresentation();
		System.out.println (s + " ==> " + v); // A(B,C) ==> (B,C)A
		System.out.println(t.toString());
	}
}