improve log message

Author: mzuenni

bin/problem.py

@@ -1061,9 +1061,13 @@ def run_submissions(problem):
         testcases, submissions = ts_pair
         ok, verdict_table = Problem.run_some(testcases, submissions)
 
-        if len(testcases) * len(submissions) > 1:
-            if not config.args.verbose and not config.args.no_visualizer:
-                log("use -v with --visualize to see the paths to the generated images")
+        if (
+            len(testcases) * len(submissions) > 1
+            and not config.args.verbose
+            and not config.args.no_visualizer
+            and problem.visualizer(visualize.OutputVisualizer)
+        ):
+            log("use -v with --visualize to see the paths to the generated images")
 
         if config.args.table:
             Problem._print_table(verdict_table.results, testcases)