vector&list 效率比较

1、比较代码（https://blog.csdn.net/libaoshan55/article/details/77337878）

 1 int main() {
 2     cout << "Test vector and list time" << endl;
 3     int N = 10000;
 4     int count = 0;
 5     while (count <= 3) {
 6         vector<int> vecInt;
 7         list<int> listInt;
 8         clock_t start, finish;
 9         cout << "N==" << N << endl;
10         start = clock();
11         for (int i = 0; i < N; ++i) {
12             vecInt.push_back(i);
13         }
14         finish = clock();
15         cout << "vector push_back 时间为" << (finish - start) << "毫秒" << endl;
16         //insert time
17         vector<int>::iterator pos_vec = vecInt.begin();
18         ++pos_vec;
19         vecInt.insert(pos_vec, 99);
20         finish = clock();
21         cout << "vector insert 时间为" << (finish - start) << "毫秒" << endl;
22 
23 
24         start = clock();
25         for (int i = 0; i < N; ++i) {
26             listInt.push_back(i);
27         }
28         finish = clock();
29         cout << "list push_back 时间为" << (finish - start) << "毫秒" << endl;
30 
31         //insert time
32         start = clock();
33         list<int>::iterator pos_ls = listInt.begin();
34         ++pos_ls;
35         listInt.insert(pos_ls, 99);
36         finish = clock();
37         cout << "list insert 时间为" << (finish - start) << "毫秒" << endl;
38 
39         //vector<int>::iterator iter = vecInt.begin();
40         //start = clock();
41         //for (; iter!=vecInt.end(); ++iter) {
42         //    *iter;
43         //}
44         //finish = clock();
45         //cout << "vector'iterator 访问元素时间为 " << (finish - start) << "毫秒" << endl;
46         //start = clock();
47         //for (int i = 0; i < vecInt.size(); ++i) {
48         //    vecInt[i];
49         //}
50         //finish = clock();
51         //cout << "vector'[] 访问元素时间为 " << (finish - start) << "毫秒" << endl;
52 
53         //start = clock();
54         //for (list<int>::iterator iter = listInt.begin(); iter != listInt.end(); ++iter) {
55         //    *iter;
56         //}
57         //finish = clock();
58         //cout << "list 访问元素时间为 " << (finish - start) << "毫秒" << endl;
59 
60         ++count;
61         N *= 10;
62         vecInt.clear();
63         listInt.clear();
64         cout << vecInt.capacity() << endl;
65 
66     }
67 }
View Code

2、vector下标[ ]与迭代器iterator遍历效率比较结果：[ ]是iterator的十倍；

3、list与vector迭代器遍历效率比较：差不多

4、list与vector的push_back()效率比较：vector远超list

5、list与vector的insert()效率比较：vector效率远低于list，根本不是一个数量级

posted @ 2020-08-05 17:43  kuaqi  阅读(1412)  评论(0)  编辑  收藏  举报