C++ STL中的multiset::swap()

Multisets是一种类似于set的关联容器，但不同的是它允许保存相同值的多个元素。

multiset::swap()

这个函数用于交换两个multisets的内容，但这两个sets的类型必须相同，尽管它们的大小可能不同。

语法:
multisetname1.swap(multisetname2)
参数：
需要交换内容的multiset的名字。

结果:
两个multiset的所有元素都被交换。

示例:

输入:  multiset1 = {1, 2, 3, 4}
      multiset2 = {5, 6, 7, 8}
      multiset1.swap(multiset2);
输出:  multiset1 = {5, 6, 7, 8}
      multiset2 = {1, 2, 3, 4}

输入:  multiset1 = {'a', 'b', 'c', 'd'}
      multiset2 = {'w', 'x', 'y', 'z'}
      multiset1.swap(multiset2);
输出:  multiset1 = {'w', 'x', 'y', 'z'}
      multiset2 = {'a', 'b', 'c', 'd'}

// INTEGER MULTISET EXAMPLE
// CPP program to illustrate
// Implementation of swap() function
#include <bits/stdc++.h>
using namespace std;
 
int main()
{
    // 取两个multisets
    multiset<int> multiset1{ 1, 2, 3, 4 };
    multiset<int> multiset2{ 5, 6, 7, 8 };
 
    // 交换multisets的元素
    multiset1.swap(multiset2);
 
    // 输出第一个multiset
    cout << "multiset1 = ";
    for (auto it = multiset1.begin();
         it != multiset1.end(); ++it)
        cout << ' ' << *it;
 
    // 输出第二个multiset
    cout << endl
         << "multiset2 = ";
    for (auto it = multiset2.begin();
         it != multiset2.end(); ++it)
        cout << ' ' << *it;
 
    return 0;
}

输出:

multiset1 =  5 6 7 8
multiset2 =  1 2 3 4

// STRING MULTISET EXAMPLE
// CPP program to illustrate
// Implementation of swap() function
#include <bits/stdc++.h>
using namespace std;
 
int main()
{
    // 取两个multisets
    multiset<string> multiset1{ "Geeksforgeeks" };
 
    multiset<string> multiset2{ "Computer science", "Portal" };
 
    // 交换multisets的元素
    multiset1.swap(multiset2);
 
    // 输出第一个multiset
    cout << "multiset1 = ";
    for (auto it = multiset1.begin();
         it != multiset1.end(); ++it)
        cout << ' ' << *it;
 
    // 输出第二个multiset
    cout << endl
         << "multiset2 = ";
    for (auto it = multiset2.begin();
         it != multiset2.end(); ++it)
        cout << ' ' << *it;
 
    return 0;
}

输出:

multiset1 =  Computer science Portal
multiset2 =  Geeksforgeeks

// CHARACTER MULTISET EXAMPLE
// CPP program to illustrate
// Implementation of swap() function
#include <bits/stdc++.h>
using namespace std;
 
int main()
{
    // 取两个multisets
    multiset<char> multiset1{ 'A', 'B', 'C' };
    multiset<char> multiset2{ 'G', 'H', 'I' };
 
    // 交换multisets的元素
    multiset1.swap(multiset2);
 
    // 输出第一个multiset
    cout << "multiset1 = ";
    for (auto it = multiset1.begin();
         it != multiset1.end(); ++it)
        cout << ' ' << *it;
 
    // 输出第二个multiset
    cout << endl
         << "multiset2 = ";
    for (auto it = multiset2.begin();
         it != multiset2.end(); ++it)
        cout << ' ' << *it;
 
    re```

输出: