数据结构 - 从一个链表中删除在另一个链表中的元素（C++）

/*Sort both list from small to big. And then use the following code.*/#include <iostream>using namespace std;struct Node{char data;Node* next;};Node* create(){Node* head = NULL;Node* rear = head;Node* p; // The pointer points to new created node.char tmp;do{cout << "Please input integer or char '#':";cin >> tmp;if(tmp != '#'){p = new Node;p->data = tmp;p->next = NULL;if(head == NULL){head = p;}else{rear->next = p;}rear = p;}}while(tmp != '#');return head;}void print(Node* head){Node* p = head;if(head != NULL){do{cout << p->data << ' ';p = p->next;}while(p != NULL);}cout << endl;}Node* del(Node* l1, Node* l2){if(!l1 || !l2){return NULL;}Node *p = new Node;p->next = l1;Node *pL1 = l1, *pL2 = l2, *head = p;while(pL1 && pL2){if(pL1->data < pL2->data){pL1 = pL1->next;p = p->next;}else if(pL1->data > pL2->data){pL2 = pL2->next;}else{pL1 = pL1->next;p->next = pL1;}}l1 = head->next;return l1;}int main(){cout << "Please input the first list:" << endl;Node* l1 = create();cout << endl << "Please input the second list:" << endl;Node* l2 = create();cout << endl << "--------------------------" << endl;cout << "The first list is: ";print(l1);cout << "The second list is: ";print(l2);Node* l = del(l1, l2);cout << endl << "The result list is: ";print(l);return 0;}// Output:/*Please input the first list:Please input integer or char '#':1Please input integer or char '#':1Please input integer or char '#':1Please input integer or char '#':1Please input integer or char '#':3Please input integer or char '#':3Please input integer or char '#':3Please input integer or char '#':3Please input integer or char '#':4Please input integer or char '#':5Please input integer or char '#':6Please input integer or char '#':6Please input integer or char '#':6Please input integer or char '#':7Please input integer or char '#':7Please input integer or char '#':8Please input integer or char '#':8Please input integer or char '#':8Please input integer or char '#':9Please input integer or char '#':9Please input integer or char '#':9Please input integer or char '#':9Please input integer or char '#':#Please input the second list:Please input integer or char '#':1Please input integer or char '#':2Please input integer or char '#':5Please input integer or char '#':5Please input integer or char '#':5Please input integer or char '#':7Please input integer or char '#':7Please input integer or char '#':7Please input integer or char '#':7Please input integer or char '#':7Please input integer or char '#':9Please input integer or char '#':#--------------------------The first list is: 1 1 1 1 3 3 3 3 4 5 6 6 6 7 7 8 8 8 9 9 9 9The second list is: 1 2 5 5 5 7 7 7 7 7 9The result list is: 3 3 3 3 4 6 6 6 8 8 8*/