Add extra consistency check.

test/test_combinatorics_c.c

@@ -90,6 +90,7 @@ main()
         ++(occCount[i][list[i]]);
     }
     failures = 0;
+    size_t occCountSum = 0;
     for (size_t j = 0; j < n; ++j)
       for (size_t i = 0; i < n; ++i)
       {
@@ -98,6 +99,7 @@ main()
         float rel_delta = abs_delta / (float)n / (float)numRuns;
         if (rel_delta > 0.01f)
           ++failures;
+        occCountSum += occCount[j][i];
       }
     if (failures > 0)
     {
@@ -111,6 +113,12 @@ main()
         fputs("\n", stdout);
       }
     }
+    if (occCountSum != n * numRuns)
+    {
+      fprintf(stderr, "n*numRuns=%zu, occCountSum=%zu\n", n*numRuns, occCountSum);
+      exit(EXIT_FAILURE);
+    }
+
   }
   free(list);
   free(occCount);