Question

我需要查找文本字符串，它是否具有嵌套循环？我可以使用正则表达式查找嵌套循环数吗？

所以我的文字示例是：

Library-Bookshelf-Book-Book-EndBookShelf-BookShelf-Book-EndBookShelf-Library

我要搜索：Whether the String belongs to the Library that has more than 1 Bookshelf in one at least has more than 1 books ?。使用正则表达式是否可能。我感谢其他任何想法。谢谢。

因此输入是上面的示例字符串。所需的输出将是找到的第一个匹配项。我需要在第一次出现时将它们拆分。

Bookshelf-Book-Book-EndBookShelf
BookShelf-Book-EndBookShelf

但是我的正则表达式返回：

Bookshelf-Book-Book-EndBookShelf-BookShelf-Book-EndBookShelf
BookShelf-Book-EndBookShelf

测试案例2：

Library-Bookshelf-Book-author-author-location-Book-author-EndBookShelf-BookShelf-Book-author-EndBookShelf-Library

使用正则表达式，我需要确定图书馆中的书架是否有超过2本书，对于一本书，它是否有一位以上的作者。 Tescase 2应该返回一个匹配项，因为第一部分Bookshelf-Book-author-author-author-location-Book-author-EndBookShelf满足条件。

谢谢..

Answer 1

这样的事情

public static void main(String[] args) {
    // TODO Auto-generated method stub

    String x = "Library-BookShelf-Book-author-author-location-Book-author-EndBookShelf-BookShelf-Book-author-EndBookShelf-Library";
    List<String> bookShelves = fun(x, "BookShelf", "EndBookShelf");
    for (String book : bookShelves)
    {
        List<String> authors = null;
        if(book.indexOf("Book") == book.lastIndexOf("Book"))
            authors = fun(book, "Book", "Book");
        else
            authors = fun(book, "Book", "EndBookShelf");
    }
}

public static List<String> fun(String input, String startTag, String endTag){

    String [] c = input.split("-");
    List<Integer> shelfIndices = getIndices(c, startTag, endTag);

    List<String> answer = new ArrayList<String>();
    int i=0;
    while (i<shelfIndices.size()-1)
    {
        int start = shelfIndices.get(i);
        int end = shelfIndices.get(i+1);
        StringBuilder res = new StringBuilder();
        res.append(startTag+"-");
        for (int j=start+1; j<end; j++)
        {
            res.append(c[j]+"-");
        }
        res.append(endTag);
        answer.add(res.toString());
        i+=2;
    }
    for(String r: answer)
        System.out.println(r);
    return answer;
}

public static List<Integer> getIndices(String [] c, String startTag, String endTag){

    List<Integer> indices = new ArrayList<Integer>();

    for (int i=0; i<c.length; i++)
    {
        if (c[i].equals(startTag) || c[i].equals(endTag))
        {
            indices.add(i);
        }
    }

    return indices;
}

这将打印出来

BookShelf-Book-author-author-location-Book-author-EndBookShelf
BookShelf-Book-author-EndBookShelf
Book-author-author-location-EndBookShelf
Book-author-EndBookShelf

Answer 2

尝试使用正则表达式：Bookshelf-(?:Book-)*EndBookShelf

Demo

嵌套字数的Java正则表达式

2 个答案: