优化

app/src/main/java/io/legado/app/ui/book/explore/ExploreShowActivity.kt

@@ -166,7 +166,12 @@ class ExploreShowActivity : VMBaseActivity<ActivityExploreShowBinding, ExploreSh
                 waitDialog.setText("添加书架中...")
             }
             books.forEach {
-                if (isInBookshelf(it.name, it.author)) return@forEach
+                appDb.bookDao.getBook(it.bookUrl)?.let { book ->
+                    book.group = book.group or groupId
+                    it.order = appDb.bookDao.minOrder - 1
+                    book.save()
+                    return@forEach
+                }
                 if (it.tocUrl.isEmpty()) {
                     val source = appDb.bookSourceDao.getBookSource(it.origin)!!
                     WebBook.getBookInfoAwait(source, it)

app/src/main/java/io/legado/app/ui/book/explore/ExploreShowViewModel.kt

@@ -74,19 +74,12 @@ class ExploreShowViewModel(application: Application) : BaseViewModel(application
         val url = exploreUrl
         if (source == null || url == null) return emptyList()
         val searchBooks = arrayListOf<SearchBook>()
-        var reverse = false
+        for (page in start .. end) {
-        val range = if (start <= end) {
-            start .. end
-        } else {
-            reverse = true
-            start downTo end
-        }
-        for (page in range) {
             val books = WebBook.exploreBookAwait(source, url, page)
             if (books.isEmpty()) break
-            if (reverse) books.reverse()
             searchBooks.addAll(books)
         }
+        searchBooks.reverse()
         return searchBooks
     }