Fix sample parsing on older tasks (#54)

* Fix sample parsing on older tasks

* Address clippy warnings

Author: UUGTech

src/ac_scraper.rs

@@ -573,16 +573,21 @@ pub async fn get_sample_cases(
     let mut outputs: Vec<(usize, String)> = Vec::new();
 
     for pre_element in pre_elements {
-        let pre_content = pre_element.text().next().context(PARSE_ERROR)?;
-        let parent_element = pre_element
-            .parent()
-            .and_then(ElementRef::wrap)
-            .context(PARSE_ERROR)?;
-        let h3_element = parent_element
-            .select(&h3_selector)
-            .next()
-            .context(PARSE_ERROR)?;
-        let h3_content = h3_element.text().next().context(PARSE_ERROR)?;
+        let pre_content = pre_element.text().collect::<String>();
+        let mut h3_content: Option<String> = None;
+        let mut cursor = pre_element.parent();
+        while let Some(node) = cursor {
+            if let Some(parent) = ElementRef::wrap(node) {
+                if let Some(h3_element) = parent.select(&h3_selector).next() {
+                    if let Some(text) = h3_element.text().next() {
+                        h3_content = Some(text.to_string());
+                        break;
+                    }
+                }
+            }
+            cursor = node.parent();
+        }
+        let h3_content = h3_content.context(PARSE_ERROR)?;
         let is_input = h3_content.contains(INPUT_HEADER);
         let is_output = h3_content.contains(OUTPUT_HEADER);
         if is_input {
@@ -592,15 +597,15 @@ pub async fn get_sample_cases(
                 .collect::<String>()
                 .parse()
                 .unwrap();
-            inputs.push((index, pre_content.into()));
+            inputs.push((index, pre_content));
         } else if is_output {
             let index: usize = h3_content
                 .chars()
                 .filter(|c| c.is_ascii_digit())
                 .collect::<String>()
                 .parse()
                 .unwrap();
-            outputs.push((index, pre_content.into()));
+            outputs.push((index, pre_content));
         }
     }
     if let Some(target) = sample_case_id_arg {