java版括號匹配檢測

做一個空棧,讀入字符直到結尾.如果讀入一個封閉符號,空棧時報錯;非空時彈出棧尾字符,如果不匹配則報錯.否則讀入為開放字符,壓入棧中.最后如果棧空,返回true.

其中用到MyStack類,詳情請見

public class KuohaoJiancha {
    private char [] item = {'(',')','[',']','{','}'};
    private MyStack stack = new MyStack();
    private char[] str;
    private int currentNum;
    public KuohaoJiancha(String str){
        this.str = str.toCharArray();;
    }

    public boolean display(){
        for(int i = 0; i < str.length; i++){
            currentNum = charNumber(str[i]);
            if(misByStackIsEmpty(str[i]))
                return false;

            if(currentNum % 2 == 1) {
                if (currentNum - charNumber((char) stack.pop()) != 1)
                    return false;
            }
            else stack.push(str[i]);
        }
        return true;
    }

    private int charNumber(char c){
        int i = 0;
        for(; i < 6; i++){
            if(c == item[i])
                break;
        }
        return i;
    }

    private boolean misByStackIsEmpty(char c){//如果讀入一個封閉符號,空棧時報錯
        if(stack.isEmpty())
            if(currentNum % 2 == 1)
                return true;
        return false;
    }

}