C++分段錯誤

Question

我想編譯我的代碼，但是一旦我嘗試InsertNode，我收到一個分段和程序崩潰。請幫助

#include <iostream> 
#include "Link.h" 

using namespace std; 

Node *createNode(){ 

    Node *newNode = new Node; 
    cout<<"Enter your first name"<<endl; 
    cin >> newNode->firstName; 
    cout<<"Enter your last name"<<endl; 
    cin>>newNode->lastName; 
    cout <<"Enter your ID Number"<<endl; 
    cin>>newNode->idNumber; 
    newNode->next=NULL; 
    return newNode; 
} 

Node *insertNode (Node *list){ 
Node *NewNode = createNode(); 
    //Node *NewNode = new Node; 
// NewNode= createNode(); 

    if(list == NULL){ 
list=NewNode; 
    } 
else{ 
Node *tmp = list; 
while(tmp->next!=NULL) 
    tmp = tmp->next; 
tmp->next=NewNode; 
} 
    return list; 
} 

Node *searchNode (Node *list){ 

    bool found=false; 
    Node *tmp=NULL; 
    int ID; 

    cout << "Enter the ID you wish to search for: "<< endl; 
    cin >> ID; 

    if(list==NULL){ 
    cout << "List is empty"<<endl; 
    return 0; 
    } 

    while(list->next!=NULL){ 
    if(ID == (list-> idNumber)){ 
     tmp=list; 
     found=true; 
    } 

    } 
    if(found=false){ 
    cout<<"Not found"<<endl; 
    return 0; 
    } 

    return tmp; 
} 

Node *deleteNode (Node *list){ 

    int ID; 

    if(list==NULL){ 
    cout <<"The list is empty"<<endl; 
    return 0; 
    } 
    cout << "Enter the ID number you wish to delete:" << endl; 
    cin >> ID; 
    if(list->idNumber==ID){ 

    Node *temp; 

    temp=list->next; 

    //free(list); 

    return temp; 
    } 

    list->next = deleteNode(list->next); 

    return list; 
} 

void printList(Node *list){ 

    Node* tmp=list; 

    if(tmp==NULL){ 
    cout<<"The list is empty"<<endl; 
    } 

    cout<< tmp-> firstName<<endl; 
    cout << tmp->lastName<<endl; 
    cout <<tmp->idNumber<<endl; 
} 

預先感謝您的任何幫助

它們被賦予用來調用任何這些函數 加入我的主菜單只是爲了告訴

#include "Link.h" 
#include <iostream> 

using namespace std; 

void DisplayMenu(); 
int main(){ 

    int answer=0; 
    Node *NewNode = new Node; 
    //NewNode = NULL; 
    do{ 
    DisplayMenu(); 
    cin >> answer; 
if(answer==1){ 
    insertNode(NewNode); 
} 
else if(answer==2){ 
deleteNode(NewNode); 
} 
else if(answer==3){ 
printList(NewNode); 
} 
else if(answer==4){ 
searchNode(NewNode); 
} 
else if(answer==5){ 
    cout << "Goodbye" << endl; 
} 
    }while(answer!=5); 





    return 0; 


} 

void DisplayMenu(){ 

    cout<< "1. Insert a node"<<endl; 
    cout<<"2. Delete a node"<<endl; 
    cout<<"3. Print List"<<endl; 
    cout<<"4. Search a node-search a node and print information for a  student."<<endl; 
    cout<<"5. Quit the program"<<endl; 
} 

Answer 1

試試這個代碼，看看你是否能看出其中的區別

int main(){ 

     int answer=0; 
     Node *list= NULL; //<---- note list variable renamed to 'list' and initialized to null 
     //NewNode = NULL; 
     do{ 
     DisplayMenu(); 
     cin >> answer; 
    if(answer==1){ 
     list = insertNode(list);  //<---- note added equals 
    } 
    else if(answer==2){ 
    deleteNode(list); 
    } 
    else if(answer==3){ 
    printList(list); 
    } 
    else if(answer==4){ 
    searchNode(list); 
    } 
    else if(answer==5){ 
     cout << "Goodbye" << endl; 
    } 
     }while(answer!=5); 


     return 0; 


    } 

Answer 2

節點.next永遠不會初始化爲null。

這導致insertNode（）的一個問題：

while(tmp->next!=NULL) <---- here 
    tmp = tmp->next;