圆括号匹配问题。(1) 圆括号包括“(), [], {}”三对；

(2) 要用到栈来进行匹配，遇到左括号进栈，遇到右括号弹栈进行匹配判断；-Parenthesis matching problem. (1) the parentheses including　(), [], {} three of

(2) to use the stack to the match, encounter left bracket into the stack, the stack met right parenthesis matching judgment