字符串练习（七）：合法括号序列判断

public class Parenthesis {
    public boolean chkParenthesis(String A, int n) {
        char[] arrC = A.toCharArray();
        int num = 0;
        int i = 0;
        while(i < arrC.length && num >= 0){
            if(arrC[i] == ‘(‘){
                num++;
            }else if(arrC[i] == ‘)‘){
                num--;
            }
            i++;
        }
         
        if(i < arrC.length || num != 0){
            return false;
        }
        return true;
    }
}