Pattern Length

Below code will find the maximum length of valid pattern i.e. pattern in which all the open brackets are closed

import java.util.Stack;

/**
 * Below code will find the maximum length of valid pattern i.e. pattern in which all the open brackets are closed
 * @author Nitin Agrawal
 *
 */
public class MaxSeries {

 public static void main(String[] args) {
  //  String str = "(([]))(())"; // 10
  //    String str = "]{[]}[]"; // 6
  //    String str = "]{{{{}}}}[]"; // 10
  String str = "{[[)[{((()))}][[[[[[[[]]]]]]]]"; // 26
  Stack<Character> stk = new Stack<>();

  int max = 0;
  int len = 0;

  for(char ch : str.toCharArray()) {
   if(ch == '(' || ch == '{' || ch == '[') {
    if(max < len) {
     max = len;
     len = 0;
    }
    stk.push(ch);
   }
   else if (ch == ')' || ch == '}' || ch == ']') {
    if(!stk.isEmpty()) {
     char ch1 = stk.pop();
     if(ch == ')' && ch1 == '(')
      len = len + 2;
     else if(ch == ']' && ch1 == '[')
      len = len + 2;
     else if(ch == '}' && ch1 == '{')
      len = len + 2;
     else {
      if(max > len) {
       max = len;
      }
      len = 0;
      stk.clear();
     }
    }
   }
  }
  if(stk.isEmpty())
   System.out.println(max+len);
  else
   System.out.println(max > len ? max : len);
 }
}