STL——容器（deque） deque 的大小

 1 #include <iostream>
 2 #include <deque>
 3 
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     deque<int> deqInt_A;
 9     deqInt_A.assign(4, 111);
10 
11     cout << "deqInt_A 中的元素个数为："<< deqInt_A.size() << endl;
12 
13     return 0;
14 }

 1 #include <iostream>
 2 #include <deque>
 3 
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     deque<int> deqInt_A,deqInt_B;
 9     deqInt_A.assign(4, 111);
10 
11     if (deqInt_A.empty())
12     {
13         cout << "deqInt_A 为空" << endl;
14     }
15     else
16     {
17         cout << "deqInt_A 不为空" << endl;
18     }
19     if (deqInt_B.empty())
20     {
21         cout << "deqInt_B 为空" << endl;
22     }
23     else
24     {
25         cout << "deqInt_B 不为空" << endl;
26     }
27     
28     return 0;
29 }

 1 #include <iostream>
 2 #include <deque>
 3 
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     deque<int> deqInt_A;
 9     deqInt_A.assign(5, 111);
10 
11     for (deque<int>::iterator it = deqInt_A.begin(); it!= deqInt_A.end(); it++)
12     {
13         cout << *it << " ";
14     }
15     
16     cout << "\n使用 resize 扩容" << endl;
17     deqInt_A.resize(10);
18     for (deque<int>::iterator it = deqInt_A.begin(); it != deqInt_A.end(); it++)
19     {
20         cout << *it << " ";
21     }
22 
23     return 0;
24 }

 1 #include <iostream>
 2 #include <deque>
 3 
 4 using namespace std;
 5 
 6 int main()
 7 {
 8     deque<int> deqInt_A;
 9     deqInt_A.assign(5, 111);
10 
11     for (deque<int>::iterator it = deqInt_A.begin(); it!= deqInt_A.end(); it++)
12     {
13         cout << *it << " ";
14     }
15     
16     cout << "\n使用 resize 扩容" << endl;
17     deqInt_A.resize(10, 222);
18     for (deque<int>::iterator it = deqInt_A.begin(); it != deqInt_A.end(); it++)
19     {
20         cout << *it << " ";
21     }
22 
23     return 0;
24 }