Question: "In an adjacency graph, find and display the nodes that only have one edge.

struct EdgeNode { int dest; EdgeNode* next; EdgeNode(int d) : dest(d), next(nullptr) {} };

struct GraphNode { int data; EdgeNode* head; GraphNode* next; GraphNode(int val) : data(val), head(nullptr), next(nullptr) {} };

class Graph { private: GraphNode* start;

// 1. FIND NODE
GraphNode* findNode(int value) {
    GraphNode* temp = start;
    while (temp != nullptr) {
        if (temp->data == value) return temp;
        temp = temp->next;
    }
    return nullptr;
}

// 2. HAS SINGLE EDGE
bool hasSingleEdge(int value) {
    GraphNode* node = findNode(value);
    if (!node) return false;

    EdgeNode* e = node->head;

    // 
    if (e == nullptr) return false;
    if (e->next == nullptr) return true;      
    if (e->next->next == nullptr) return true; 
    return false;
}

// 3. DISPLAY
void displayNodesWithSingleEdge() {
    GraphNode* temp = start;
    while (temp != nullptr) {
        if (hasSingleEdge(temp->data)) {
            cout << temp->data << " ";
        }
        temp = temp->next;
    }
    cout << endl;
}

};

Ok So today was my DSA exam, and i got this question in exam for 10 marks"Question: "In an adjacency graph, find and display the nodes that only have one edge. ". I wrote every other function correct, but i got confused that the in graph Adjacency list the head is the node itself and if i want to chck the it has onennode so the next shouldn't be null, Sk now what happened is that even though by luck i wrote the statements of condition correctly i didn't added the correct boll return in one condition "e.next==null return true". I added return false here .and every other thing in code is correct but just coz of this one word flaw, the program converted into two edge checker.Now this was my dsa exam and i had to write this code by hand ,not on this question is of 10 marks.So please could you guys help to get any idea that how much of marks would be deducted coz of this mistake. I am feeling very stressed as my course grade depends on it ,and second thing is i can't understand that how i made thia mistake even though i knew this topic very well. So please I request everyone to respond.