[ORACLEJAVA커뮤니티]스택을 응용한 문자열 뒤집기, 괄호체크 하기

오라클자바커뮤니티에서 설립한 오엔제이프로그래밍 실무교육센터

(신입사원채용무료교육, 오라클SQL, 튜닝, 힌트,자바프레임워크, 안드로이드, 아이폰, 닷넷)  

www.onjprogramming.co.kr

//Stack을 응용한 문자열 뒤집기, 괄호체크 하기
public class StackApp {
  public static String reverseString (String str )    {
//Create a new stack
Stack stk = new ArrayStack();
// push each character into stack
for (int i = 0; i < str.length(); i++)  {
char ch = str.charAt(i);
stk.push( new Character(ch));
}
String ret="";
    for (int i = 0; i < str.length(); i++) {
    char charFromStack = ((Character)stk.pop()).charValue();
        ret = ret + charFromStack;
    }
    return ret;
  }

  public static boolean bracketsBalance (String exp) {
    ArrayStack stk = new ArrayStack(exp.length() +1); 
    for (int i = 0; i < exp.length(); i++) {
        //Scan across the expression
        char ch = exp.charAt(i);
        if (  ch== '[' || ch == '('  )  {
            stk.push( new Character(ch));
        }         
 else if(ch == ']' || ch == ')')  { 
  //empty means brackets unmatched
 if (stk.isEmpty())  return false;
 char charFromStack = ((Character)stk.pop()).charValue();
 if (  ch == ']' && charFromStack != '[' 
  ||  (ch == ')' && charFromStack != '(')  )
  return false;
} // end if
} // end for loop
    return stk.isEmpty();  //empty means matched,  else unmatched
}
       
  public static void main(String args[]) {   
      if (args.length < 2)  {
  System.out.println("Usage : java StackApp String1 String2");
  System.exit(1);
      }
  String s1 = args[0];
  String s2 = args[1];

  System.out.println(s1 + " : " + reverseString(s1));

  if (bracketsBalance(s2))  {
  System.out.println("괄호가  정확함");
  }
  else {
  System.out.println("괄호가 부정확 함");
  }   
  }
}

[출처] 오라클자바커뮤니티 - http://www.oraclejavanew.kr/bbs/board.php?bo_table=LecJavaAlgorithm&wr_id=45