C++ unordered_multimap swap()用法及代码示例

unordered_multimap::swap()是C++ STL中的内置函数，该函数交换两个unordered_multimap容器的内容。两个容器的尺寸可能不同。

用法:

unordered_multimap_name1.swap(unordered_multimap_name2)

参数：该函数接受单个强制性参数unordered_multimap_name2，该参数指定与unordered_multimap_name1进行交换的unordered_multimap。

返回值：它不返回任何东西。

以下示例程序旨在说明上述函数：

示例1:

// C++ program to illustrate the 
// unordered_multimap::swap() 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
  
    // declaration 
    unordered_multimap<int, int> sample1, sample2; 
  
    // inserts key and element 
    // in sample1 
    sample1.insert({ 10, 100 }); 
    sample1.insert({ 50, 500 }); 
  
    // inserts key and element 
    // in sample1 
    sample2.insert({ 20, 200 }); 
    sample2.insert({ 30, 300 }); 
    sample2.insert({ 30, 150 }); 
  
    cout << "Key and Elements of Sample1 before swap are:"; 
    for (auto it = sample1.begin(); it != sample1.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    cout << "\nKey and Elements of Sample2 before swap are:"; 
    for (auto it = sample2.begin(); it != sample2.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    // performs swap of two 
    // unordered_multimaps 
    sample1.swap(sample2); 
  
    cout << "\n\nKey and Elements of Sample1 after swap are:"; 
    for (auto it = sample1.begin(); it != sample1.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    cout << "\nKey and Elements of Sample2 after swap are:"; 
    for (auto it = sample2.begin(); it != sample2.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    return 0; 
}

输出：

Key and Elements of Sample1 before swap are:{50, 500} {10, 100} 
Key and Elements of Sample2 before swap are:{20, 200} {30, 150} {30, 300} 

Key and Elements of Sample1 after swap are:{20, 200} {30, 150} {30, 300} 
Key and Elements of Sample2 after swap are:{50, 500} {10, 100}

示例2:

// C++ program to illustrate the 
// unordered_multimap::swap() 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
  
    // declaration 
    unordered_multimap<char, char> sample1, sample2; 
  
    // inserts key and element 
    // in sample1 
    sample1.insert({ 'a', 'A' }); 
    sample1.insert({ 'g', 'G' }); 
  
    // inserts key and element 
    // in sample1 
    sample2.insert({ 'b', 'B' }); 
    sample2.insert({ 'c', 'C' }); 
    sample2.insert({ 'd', 'D' }); 
  
    cout << "Key and Elements of Sample1 before swap are:"; 
    for (auto it = sample1.begin(); it != sample1.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    cout << "\nKey and Elements of Sample2 before swap are:"; 
    for (auto it = sample2.begin(); it != sample2.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    // performs swap of two 
    // unordered_multimaps 
    sample1.swap(sample2); 
  
    cout << "\n\nKey and Elements of Sample1 after swap are:"; 
    for (auto it = sample1.begin(); it != sample1.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    cout << "\nKey and Elements of Sample2 after swap are:"; 
    for (auto it = sample2.begin(); it != sample2.end(); it++) { 
        cout << "{" << it->first << ", " << it->second << "} "; 
    } 
  
    return 0; 
}

输出：

Key and Elements of Sample1 before swap are:{g, G} {a, A} 
Key and Elements of Sample2 before swap are:{d, D} {b, B} {c, C} 

Key and Elements of Sample1 after swap are:{d, D} {b, B} {c, C} 
Key and Elements of Sample2 after swap are:{g, G} {a, A}

相关用法

注：本文由纯净天空筛选整理自gopaldave大神的英文原创作品 unordered_multimap swap() function in C++ STL。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。