Fourth time assignment

    ImportJava.util.Stack;  Public classOperate {PrivateStack<character> Pristack =NewStack<character>(); PrivateStack<integer> Numstack =NewStack<integer>();;  Public intcaculate (String str) {string temp; StringBuffer Tempnum=NewStringBuffer (); StringBuffer string=NewStringBuffer (). append (str);  while(String.Length ()! = 0) {Temp= string.substring (0, 1); String.delete (0, 1); if(!Isnum (temp)) {                                             if(!"". Equals (Tempnum.tostring ())) {                                                     intnum =Integer.parseint (tempnum.tostring ());                          Numstack.push (num); Tempnum.delete (0, Tempnum.length ()); }                                              while(Ompare (Temp.charat (0)) && (!Pristack.empty ())) {                           intA = (int) Numstack.pop (); intB = (int) Numstack.pop (); CharOpe =Pristack.pop (); intresult = 0; Switch(ope) { Case+: Result= B +A;                                  Numstack.push (result);  Break;  Case‘-‘: Result= B-A;                                  Numstack.push (result);  Break;  Case‘*‘: Result= b *A;                                  Numstack.push (result);  Break;  Case‘/‘: Result= b/A;                                  Numstack.push (result);  Break; }                                    }                                                    if(Temp.charat (0)! = ' # ') {Pristack.push (NewCharacter (Temp.charat (0))); if(Temp.charat (0) = = ') ') {pristack.pop ();                              Pristack.pop (); }                          }                      } ElseTempnum=tempnum.append (temp); }                  returnNumstack.pop (); }                                  Private Booleanisnum (String temp) {returnTemp.matches ("[0-9]"); }                                  Private BooleanCompareCharstr) {                  if(Pristack.empty ()) {return true; }                  CharLast = (Char) pristack.lastelement (); if(Last = = ' (') {                      return true; }                  Switch(str) { Case‘#‘:                      return false;  Case‘(‘:                                            return true;  Case‘)‘:                                           return false;  Case‘*‘: {                                           if(last = = ' + ' | | last = = '-'))                          return true; Else                          return false; }                   Case‘/‘: {                      if(last = = ' + ' | | last = = '-'))                          return true; Else                          return false; }                                         Case+:                      return false;  Case‘-‘:                      return false; }                  return true; }                         Public Static voidMain (String args[]) {Operate Operate=NewOperate (); intt = Operate.caculate ("(3+4* (4*10-10/2) #");              System.out.println (t); }                    }      

Requirement Analysis: Input 0-10 random number, calculate subtraction's arithmetic.

Summary: With the completion of the third job, the fourth time the assignment is only to add a little content, but I have not a bit of thinking, but also looked at the partner to do, only slowly have a train of thought, write not good please teacher understanding.

Fourth time assignment