如何在C++中打印出以下实现的链接列表

Question

我刚刚完成了制作链表的程序，也应该打印出内容。 它编译正确，似乎可以制作链表，但似乎没有打印出任何东西。 关于我在这里做错了什么的任何建议？

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;

struct DeltaTimerNode
{
    int timerInterval;
    DeltaTimerNode *next;
    DeltaTimerNode(int tempTimeInt, DeltaTimerNode *tempNext = NULL)
    {
        timerInterval = tempTimeInt;
        next = tempNext;
    }
};

DeltaTimerNode *deltaTimerList = NULL;
void insert(int deltaTimerValue)
{
    deltaTimerList = new DeltaTimerNode (deltaTimerValue, deltaTimerList);
}


int main()
{
    int tickTime;
    char choice;
    vector<int> rawTimers;
//int i = 0; Originally used for tracking something.  Moved logic to different function.

    do 
    {
        cout<< "Input timer value (not delta timer)." << endl;
        cin >> tickTime; //Input regular value of timer, not the delta time.  That will be converted automatically.
        rawTimers.push_back(tickTime);
        //i++;
        cout<< "Are there more timer values?  Input y for yes, n for no."<<endl;
        cin >> choice;
    }
    while(choice == 'y');

    sort (rawTimers.begin(), rawTimers.end());
    DeltaTimerNode *deltaTimerList = NULL;
    for (int j = 0; j < rawTimers.size(); j++) //for loop populates list.
    {
        if (j == 0)
        {
            insert (rawTimers[0]);
        }
        else
        {
            insert (rawTimers[j] - rawTimers[j-1]);
        }
    }

    DeltaTimerNode *ptr = deltaTimerList;
    while (ptr != NULL)
    {
        cout << ptr -> timerInterval << " "; //should print out stuff here.
        ptr = ptr -> next;
    }
    return 0;   
}

Answer 1

您声明了一个局部变量deltaTimerList并遮蔽了 gloval 变量deltaTimerList。删除有害声明

DeltaTimerNode *deltaTimerList = NULL;

从main().

另请注意，您应该通过delete销毁您通过new创建的任何内容。

Answer 2

首先，您需要删除结构中的默认构造函数，并且不需要insert（）函数和全局变量。只需创建一个新节点，并在每次使用节点时将指针指定为新节点即可。我希望你明白这个想法，这应该有效：

#include <iostream>
#include <algorithm>
#include <vector>
using namespace std;
struct DeltaTimerNode
{
    int timerInterval;
    DeltaTimerNode *next;
};
int main()
{
int tickTime;
char choice;
vector<int> rawTimers;
do
{
    cout << "Input timer value (not delta timer)." << endl;
    cin >> tickTime; //Input regular value of timer, not the delta time.  That will be converted automatically.
    rawTimers.push_back(tickTime);
    cout << "Are there more timer values?  Input y for yes, n for no." << endl;
    cin >> choice;
} while (choice == 'y');
sort(rawTimers.begin(), rawTimers.end());
DeltaTimerNode deltaTimerList;
DeltaTimerNode* head = &deltaTimerList;
for (int j = 0; j < rawTimers.size(); j++) //for loop populates list.
{
    if (j == 0)
    {
        head->timerInterval = rawTimers[j];
        head->next = new DeltaTimerNode();
        head = head->next;
    }
    else
    {
        head->timerInterval = rawTimers[j] - rawTimers[j - 1];
        head->next = new DeltaTimerNode();
        head = head->next;
    }
}
head = &deltaTimerList;
while (head->next != NULL)
{
    cout << head->timerInterval << " "; //should print out stuff here.
    head = head->next;
}
return 0;

}