Question

    static List<String> openingBrackets = new ArrayList<String>();
    static List<String> closingBrackets = new ArrayList<String>();

    public static final String quit = ""; // to be used in sentinel loop

    public static void main(String[] args)
    {
        Scanner scanner = new Scanner(System.in);

        // list containing all the opening brackets
        openingBrackets.add("(");
        openingBrackets.add("{");
        openingBrackets.add("[");
        openingBrackets.add("<");
        System.out.println(openingBrackets);

        // list that contains the closing brackets
        closingBrackets.add(")");
        closingBrackets.add("}");
        closingBrackets.add("]");
        closingBrackets.add(">");
        System.out.println(closingBrackets);

        String sent = "value"; // some dummy value assigned to sent.

        // creating a stack to store the opening brackets
        Stack stackOpening = new Stack();

        // creating a stack to store the closing brackets
        Stack stackClosing = new Stack(); 

        while (!sent.equals(quit))
        {
            System.out.println("Enter a string to test:");
            sent = scanner.nextLine();

            for (int i=0; i<sent.length(); i++)
            {
                char c = sent.charAt(i);

                if (! openingBrackets.contains(c))
                {
                    // push the opening brackets in the String sent 
                    // in the Stack for opening brackets

                    stackOpening.push(c); 
                }

                if (! closingBrackets.contains(c))
                {
                    // push only the closing brackets in the String
                    // in the stack for closing brackets

                    stackClosing.push(c);
                }
            }
        }
    }
}

示例输入：

(< [ { } ( { > ) ] >

示例输出：

堆叠（用于打开括号）：[ (, <, [, {, }, (, { ]
堆叠（用于关闭括号）：[ >, ), ], > ]

但是，分别打印两个堆栈时;输出 s

[ (, <, [, {, }, (, {, >, ), ], > ]

Answer 1

openingBrackets和closingBrackets是String的{{3}}个。但是，如果这些集合包含Collection s：

，请检查

char c = sent.charAt(i);

if (! openingBrackets.contains(c))

由于Collection不包含任何Character，因此未找到任何匹配项，这就是为什么所有元素都会添加到Stack s。

要解决此问题，请先测试openingBrackets的{{1}}和closingBrackets Collection，或在测试前将Character转换为c，如果它包含在其中一个String中。

（大多数Collection检查，如果它们使用Character方法包含元素，Collection和String仅返回Character，如果两个实例属于同一类型）

使用包含括号的列表将特定括号（打开，关闭）存储在堆栈中

1 个答案: