STL——容器（deque） deque 的赋值 assign() operator=() swap()

deque 的赋值分下边4种方法：

deque.assign(beg,end);

//将[beg, end)区间中的数据拷贝赋值给本身。注意该区间是左闭右开的区间。

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

打印结果：

deque.assign(n,elem);

//将n个elem拷贝赋值给本身。

 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, 888);
10
11     cout << "deqInt_A 中的元素为：" << endl;
12     for (deque<int>::iterator it = deqInt_A.begin(); it != deqInt_A.end(); it++)
13     {
14         cout << *it << " ";
15     }
16
17     return 0;
18 }

打印结果：

deque& operator=(const deque &deq);

//重载等号操作符

 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, 888);
10     deqint_B = deqInt_A;            // operator= 重载，可以直接进行赋值
11
12     cout << "deqint_B 中的元素为：" << endl;
13     for (deque<int>::iterator it = deqint_B.begin(); it != deqint_B.end(); it++)
14     {
15         cout << *it << " ";
16     }
17
18     return 0;
19 }

打印结果：

deque.swap(deq);

// 将deque与本身的元素互换

 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     deqint_B.assign(5, 222);
11
12     cout << "deqInt_A 中的元素为：" << endl;
13     for (deque<int>::iterator it = deqInt_A.begin(); it != deqInt_A.end(); it++)
14     {
15         cout << *it << " ";
16     }
17     cout << "\ndeqint_B 中的元素为：" << endl;
18     for (deque<int>::iterator it = deqint_B.begin(); it != deqint_B.end(); it++)
19     {
20         cout << *it << " ";
21     }
22     cout << "\n\nswap 进行翻转" << endl;
23     deqInt_A.swap(deqint_B);
24     cout << "deqInt_A 中的元素为：" << endl;
25     for (deque<int>::iterator it = deqInt_A.begin(); it != deqInt_A.end(); it++)
26     {
27         cout << *it << " ";
28     }
29     cout << "\ndeqint_B 中的元素为：" << endl;
30     for (deque<int>::iterator it = deqint_B.begin(); it != deqint_B.end(); it++)
31     {
32         cout << *it << " ";
33     }
34     return 0;
35 }

打印结果：

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