void loadFromFile(const string& filename) { ifstream file(filename); string line; int number = 1; while (getline(file, line)) { float result = stof(line); Athlete* newAthlete = new Athlete{ number++, result, nullptr }; if (head == nullptr) { head = newAthlete; } else { Athlete* current = head; while (current->next != nullptr) { current = current->next; } current->next = newAthlete; } } }改为头节点不存放数据

可以将头节点设置为空节点，不存放数据，如下所示：

void loadFromFile(const string& filename) {
    ifstream file(filename);
    string line;
    int number = 1;
    Athlete* current = new Athlete{ 0, 0, nullptr };
    head = current;
    while (getline(file, line)) {
        float result = stof(line);
        Athlete* newAthlete = new Athlete{ number++, result, nullptr };
        current->next = newAthlete;
        current = newAthlete;
    }
    current->next = nullptr; // 将最后一个节点的 next 指针设为空
    current = head; // 重置 current 指针
    head = head->next; // 将头节点指向第一个有效节点
    delete current; // 释放空节点的内存
}

这样头节点就不存放数据了，而是一个空节点，可以方便地进行链表操作。注意在函数结束前要释放空节点的内存。