swap
描述 (Description)
C ++函数std::vector::swap()交换两个向量的内容。
声明 (Declaration)
以下是std :: vector :: swap()函数形式std :: vector标头的声明。
template <class T, class Alloc>
void swap (vector<T,Alloc>& v1, vector<T,Alloc>& v2);
参数 (Parameters)
v1 - 第一个矢量容器。
v2 - 第二个向量容器。
返回值
没有。
异常 (Exceptions)
这个函数永远不会抛出异常。
时间复杂
线性即O(n)
例子 (Example)
以下示例显示了std :: vector :: swap()函数的用法。
#include <iostream>
#include <vector>
using namespace std;
int main(void) {
vector<int> v1 = {1, 2, 3, 4, 5};
vector<int> v2 = {10, 20, 30};
cout << "Contents of vector v1 before swap operation" << endl;
for (int i = 0; i < v1.size(); ++i)
cout << v1[i] << endl;
cout << "Contents of vector v2 before swap operation" << endl;
for (int i = 0; i < v2.size(); ++i)
cout << v2[i] << endl;
swap(v1, v2);
cout << "Contents of vector v1 after swap operation" << endl;
for (int i = 0; i < v1.size(); ++i)
cout << v1[i] << endl;
cout << "Contents of vector v2 after swap operation" << endl;
for (int i = 0; i < v2.size(); ++i)
cout << v2[i] << endl;
return 0;
}
让我们编译并运行上面的程序,这将产生以下结果 -
Contents of vector v1 before swap operation
1
2
3
4
5
Contents of vector v2 befor swap operation
10
20
30
Contents of vector v1 after swap operation
10
20
30
Contents of vector v2 after swap operation
1
2
3
4
5