c++ - C ++单链表从头开始查找节点值x个空格

Question

float get(int x) {
        if(x == 0) {return head->x;}
        else {
            Node *current = head;
            for(int a=0; a<x; a++) {
                current = current->next;
            }
            return current->x;
        }
    }

这是我的代码，但是当我使用测试用例运行它时，它显示“Lab3.exe 已停止工作”。我对 C++ 还是很陌生，我们的老师丝毫没有帮助，有人可以就我的实现给我建议吗？

编辑：这是测试用例......

#include <iostream>
#include <string>
using namespace std;

// including _my copy_ of SLList
#include "./SLList.h"
using namespace ods;

template <class FloatList>
bool listTest(){
    FloatList L;
    L.add(0, 3.14);
    L.remove(0);
    L.add(0, 1.62);
    L.add(1, 2.23);
    L.set(1, 2.72);
    /*float x = L.get(1);*/
    return ( 2.72f == L.get(1) and 2 == L.size() );
}

int main() {
    if ( listTest<SLList<float> >() )
        cout << "SLList passes basic list interface test" << endl;
    else 
        cout << "SLList FAILS basic list interface test" << endl;
}

以下是 SLL 的设置方式：

template<class T>
class SLList {
    T null;
protected:
    class Node {
    public:
        T x;
        Node *next;
        Node(T x0) {
            x = 0;
            next = NULL;
        }
    };
    Node *head;
    Node *tail;
    int n;

public:

    SLList() {
        null = (T)NULL;
        n = 0;
        head = tail = NULL;
    }

    virtual ~SLList() {
        Node *u = head;
        while (u != NULL) {
            Node *w = u;
            u = u->next;
            delete w;
        }
    }