@@ -30,6 +30,8 @@ public:
3030 bool delete_my_new(Element * elem);
3131 Element* GetHead();
3232 Element* GetTail();
33+ int GetHeadValue();
34+ int GetTailValue();
3335private:
3436 Element* head = nullptr;
3537 Element* tail = nullptr;
@@ -44,6 +46,20 @@ Element* my_list::GetTail(){
4446 return this->tail;
4547}
4648
49+ int my_list::GetHeadValue (){
50+ if(this->head != nullptr){
51+ return this->head->data;
52+ }
53+ return -1;
54+ }
55+ 56+ int my_list::GetTailValue (){
57+ if(this->tail != nullptr){
58+ return this->tail->data;
59+ }
60+ return -1;
61+ }
62+ 4763Element* my_list::GetBeforeEndElement (){
4864 if(this->head == nullptr || this->head == this->tail){
4965 return nullptr;
@@ -92,11 +108,14 @@ bool my_list::delete_my(Element *elem){
92108 }
93109
94110 if(elem == this->head){
95- this->head = this->head->next;
96111 if(this->head->next == nullptr){
112+ this->head = nullptr;
97113 this->tail = nullptr;
98114 }
99- delete elem;
115+ else{
116+ this->head = this->head->next;
117+ delete(elem);
118+ }
100119 return true;
101120 }
102121
@@ -105,7 +124,13 @@ bool my_list::delete_my(Element *elem){
105124 if(beforeEnd != nullptr){
106125 beforeEnd->next = nullptr;
107126 this->tail = beforeEnd;
108- delete elem;
127+ delete(elem);
128+ return true;
129+ }
130+ else{
131+ this->head = nullptr;
132+ this->tail = nullptr;
133+ delete(elem);
109134 return true;
110135 }
111136 }
@@ -123,6 +148,7 @@ bool my_list::delete_my(Element *elem){
123148 return false;
124149};
125150
151+ // 向头部插入结点
126152bool my_list::insertAfter(Element * elem, int data){
127153 if(elem == NULL){
128154 Element* e = new Element;
@@ -133,37 +159,40 @@ bool my_list::insertAfter(Element *elem, int data){
133159 this->tail = e;
134160 return true;
135161 }
162+ else{
163+ this->head = e;
164+ return true;
165+ }
136166 }
137167 return false;
138168}
139169
140170int main(){
141171 my_list myList;
142- 143- Element* e1 = new Element;
144- e1->data = 10;
145- e1->next = nullptr;
146- 147- Element* e2 = new Element;
148- e2->data = 20;
149- e2->next = nullptr;
150- 151- myList.insertAfter(nullptr, 5);
152172 myList.insertAfter(nullptr, 1);
173+ myList.insertAfter(nullptr, 2);
174+ myList.insertAfter(nullptr, 3);
175+ myList.insertAfter(nullptr, 4);
176+ std::cout << myList.GetHeadValue() << std::endl;
177+ std::cout << myList.GetTailValue() << std::endl;
153178
154179 // 删除第一个节点
155180 if (myList.delete_my(myList.GetHead())) {
156181 std::cout << "Deleted first element." << std::endl;
157182 } else {
158- std::cout << "Failed to delete element ." << std::endl;
183+ std::cout << "Failed to delete element1 ." << std::endl;
159184 }
185+ std::cout << myList.GetHeadValue() << std::endl;
186+ std::cout << myList.GetTailValue() << std::endl;
160187
161188 // 删除最后一个节点
162189 if (myList.delete_my(myList.GetTail())) {
163190 std::cout << "Deleted last element." << std::endl;
164191 } else {
165- std::cout << "Failed to delete element ." << std::endl;
192+ std::cout << "Failed to delete element2 ." << std::endl;
166193 }
194+ std::cout << myList.GetHeadValue() << std::endl;
195+ std::cout << myList.GetTailValue() << std::endl;
167196
168197 return 0;
169198}
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