Change example solution to accomodate new test cases

exercises/practice/grade-school/.meta/example.cpp

@@ -1,22 +1,27 @@
 #include "grade_school.h"
-#include <algorithm>
 
-using namespace std;
+namespace grade_school {
+    void school::add(std::string const& name, int grade) {
+        // Check if the student already exists
+        if (students_.find(name) != students_.end())
+        {
+            // Student already exists; do not add
+            return;
+        }
+        // Add the student to the set of students
+        students_.insert(name);
+        // Proceed to add the student to the given grade in sorted order
+        std::vector<std::string>& grade_roster = roster_[grade];
+        auto it = lower_bound(grade_roster.begin(), grade_roster.end(), name);
+        grade_roster.insert(it, name);
+    }
 
-namespace grade_school
-{
+    std::vector<std::string> school::grade(int grade) const
+    {
+        auto it = roster_.find(grade);
+        return (it != roster_.end()) ? it->second : std::vector<std::string>{};
+    }
 
-void school::add(string const& name, int grade)
-{
-    vector<string>& grade_roster = roster_[grade];
-    auto it = lower_bound(grade_roster.begin(), grade_roster.end(), name);
-    grade_roster.insert(it, name);
-}
 
-vector<string> school::grade(int grade) const
-{
-    auto it = roster_.find(grade);
-    return (it != roster_.end()) ? it->second : vector<string>{};
-}
+}  // namespace grade_school
 
-}

exercises/practice/grade-school/.meta/example.h

@@ -1,28 +1,26 @@
-#if !defined(GRADE_SCHOOL_H)
-#define GRADE_SCHOOL_H
-
-#include <map>
-#include <string>
+#include <set>
 #include <vector>
+#include <string>
+#include <map>
 
 namespace grade_school
 {
 
-class school
-{
-public:
-    const std::map<int, std::vector<std::string>>& roster() const {
-        return roster_;
-    }
+    class school
+    {
+        public:
+            const std::map<int, std::vector<std::string>>& roster() const {
+                return roster_;
+            }
 
-    void add(std::string const& name, int grade);
+            void add(std::string const& name, int grade);
 
-    std::vector<std::string> grade(int grade) const;
+            std::vector<std::string> grade(int grade) const;
 
-private:
-    std::map<int, std::vector<std::string>> roster_;
-};
+        private:
+            std::map<int, std::vector<std::string>> roster_;
+            std::set<std::string> students_; // New member to track existing students
+    };
 
 }
 
-#endif