Valid Parentheses @LeetCode

 
package Level2;  
  
import java.util.Stack;  
  
/** 
 * 
 * Valid Parentheses 
 *  
 * Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. 
 
The brackets must close in the correct order, "()" and "()[]{}" are all valid but "(]" and "([)]" are not. 
 * 
 */  
public class S20 {  
  
    public static void main(String[] args) {  
  
    }  
      
    // 用stack来检查  
    public boolean isValid(String s) {  
        Stack stack = new Stack();  
        for(int i=0; i