list对象指针与指针类型list

Posted 2020-09-30 peki10

 

 1 #include <string>
 2 #include <cctype>
 3 #include <algorithm>
 4 #include <iostream>
 5 #include <list>
 6 using namespace std;
 7 class Base{
 8 public:
 9         int data;
10         Base(int y):data(y){}
11 };
12 Base *pt(int x){
13         Base *tmp = new Base(x);
14         return tmp;
15 }
16 int main()
17 {
18 
19         string str("ceshi andx 123 benjing");
20         int x = 0;
21         char first[6] = {0};
22         char last[16] = {0};
23         char mid[16] = {0};
24         int ret = sscanf(str.c_str(), "%s%s%d%s", first, mid, &x, last);
25         cout << ret <<  " first:" << first << " mid:" << mid << " x:" << x << " last:" << last << endl;
26 
27         //int指针类型的list
28         list<int *> intptr;
29         int *tmp = new int[5];
30         for(int i=0; i<5; i++){
31                 tmp[i] = i;
32                 intptr.push_back(&tmp[i]);
33         }
34         list<int *>::iterator liter;
35         for(liter  = intptr.begin(); liter != intptr.end(); ++liter)
36                 cout << **liter << endl;
37         for (std::list<int*>::iterator it = intptr.begin(); it != intptr.end();it++)
38         {
39                 //delete &it; //error
40         }
41         delete[] tmp;
42 
43         //以下list对象指针均建立在堆上，需要new/delete结合申请与释放
44         //list元素为基本数据类型的对象指针      
45         list<int> *ptr = new list<int>[2]; 
46         ptr->push_back(2);
47         ptr->push_back(3);
48         list<int>::iterator iter;
49         for(iter  = ptr->begin(); iter != ptr->end(); ++iter)
50                 cout << *iter << endl;
51         delete[] ptr;
52         //list元素为自定义类型的对象指针
53         list<Base> *pBase = new list<Base>[5];
54         Base ba(4);
55         Base bb(5);
56         pBase->push_back(ba);
57         pBase->push_back(bb);
58         list<Base>::iterator iterb;
59         for(iterb  = pBase->begin(); iterb != pBase->end(); ++iterb)
60                 cout << (*iterb).data << endl;
61         delete[] pBase;
62 
63 }