panic when the problem is locked

Author: yue2388253

src/main.rs

@@ -41,7 +41,9 @@ fn main() {
         }
 
         let problem = problem::get_problem(id)
-            .expect(&format!("problem #{} not found", id));
+            .expect(&format!("Error: failed to get problem #{} \
+                              (The problem may be paid-only or may not be exist).",
+                             id));
         let code = problem.code_definition.iter()
             .filter(|&d| { d.value == "rust" })
             .next();

src/problem.rs

@@ -21,6 +21,11 @@ pub fn get_problem(id: u32) -> Option<Problem> {
     let problems = get_problems().unwrap();
     for problem in problems.stat_status_pairs.iter() {
         if problem.stat.question_id == id {
+
+            if problem.paid_only {
+                return None
+            }
+
             let client = reqwest::Client::new();
             let resp: RawProblem = client.post(GRAPHQL_URL)
                 .json(&Query::question_query(problem.stat.question_title_slug.as_ref().unwrap()))