1 package algorithms.exercise; 2 3 import algorithms.ADT.Stack; 4 import algorithms.util.StdIn; 5 import algorithms.util.StdOut; 6 7 8 /************************************************************************* 9 * 10 * % java Ex_1_3_09 11 * 1 + 2 ) * 3 - 4 ) * 5 - 6 ) ) ) 12 * ( ( 1 + 2 ) * ( ( 3 - 4 ) * ( 5 - 6 ) ) ) 13 * 14 * % java Ex_1_3_09 15 * sqrt 1 + 2 ) ) 16 * ( sqrt ( 1 + 2 ) ) 17 * 18 *************************************************************************/ 19 20 public class Ex_1_3_09 21 { 22 public static void main(String[] args) 23 { 24 Stack<String> ops = new Stack<String>(); 25 Stack<String> vals = new Stack<String>(); 26 27 while (!StdIn.isEmpty()) 28 { 29 String s = StdIn.readString(); 30 31 if (s.equals("(")) ; 32 else if (s.equals("+") || 33 s.equals("-") || 34 s.equals("*") || 35 s.equals("/") || 36 s.equals("sqrt")) ops.push(s); 37 else if (s.equals(")")) 38 { 39 String op = ops.pop(); 40 String v = vals.pop(); 41 42 if (op.equals("+") || 43 op.equals("-") || 44 op.equals("*") || 45 op.equals("/")) 46 v = String.format("( %s %s %s )", vals.pop(), op, v); 47 else if (op.equals("sqrt")) 48 v = String.format("( %s %s )", op, v); 49 50 vals.push(v); 51 } 52 else vals.push(s); 53 //else vals.push(((Double)Double.parseDouble(s)).toString()); 54 } 55 56 StdOut.println(vals.pop()); 57 } 58 }