C++典型实现补充

code_segment/test.cpp

@@ -0,0 +1,98 @@
+#include <iostream>
+#include <vector>
+#include <map>
+using namespace std;
+struct ListNode{
+    ListNode(int a){
+        val = a;
+    }
+    ListNode* pre;
+    ListNode* next;
+    int val;
+};
+
+class Data{
+public:
+    ListNode* head;
+    ListNode* end;
+    map<int,ListNode*> m;
+    int size;
+    
+    Data(){
+        head = new ListNode(-1);
+        end  = head;
+        size=0;
+    }
+    void set(int a){
+        ListNode* temp;
+        if(size==4){
+            temp = end;
+            end = end->pre;
+            m.erase(temp->val);
+            delete temp;
+            size--;
+        }
+
+
+        ListNode* n = new ListNode(a);
+        m[a]=n;
+        if(size==0){
+            head->next =n;
+            n->pre=head;
+            end = n;
+            size=1;
+        }
+        else{
+            temp = head->next;
+            head->next = n;
+            n->pre = head;
+            n->next = temp;
+            temp->pre = n;
+            size++;
+        }
+
+    }
+    ListNode* get(int a){
+        ListNode* temp = m[a];
+        if(temp==head->next){
+            return temp;
+        }
+        if(temp==end){
+            end = end->pre;
+        }
+        temp->pre->next = temp->next;
+        temp->next->pre = temp->pre;
+        ListNode* n = head->next;
+        temp->next = n;
+        n->pre = temp;
+        head->next = temp;
+        temp->pre = head;
+        
+        return temp;
+    }
+    ListNode* get(){
+        return head->next;
+    }
+    ~Data(){
+        ListNode* temp=head;
+        while(temp!=nullptr){
+            ListNode* n = temp;
+            delete n;
+            temp=temp->next;
+        }
+    }
+};
+int main() {
+    Data data;
+    data.set(1);
+    cout<<data.get()->val<<endl;
+    data.set(2);
+    data.set(3);
+    
+    ListNode* temp = data.get(2);
+    cout<<temp->val<<endl;
+    temp = data.get();
+    cout<<temp->val<<endl;
+
+    cout << "Hello World!" << endl;
+}