C++ Operator> 是C++中multimap的非成员重载函数。此函数用于检查第一个multimap是否大于其他multimap。
template <class Key, class T, class Compare, class Alloc> bool operator> ( const multimap<Key,T,Compare,Alloc>& lhs, const multimap<Key,T,Compare,Alloc>& rhs );
lhs :第一个multimap对象。
rhs :第二个multimap对象。
如果multimap集合对象的左侧大于multimap对象的右侧,则返回 true ,否则返回 false 。
让我们看一个简单的示例,以检查第一个multimap是否大于:
链接:https://www.learnfk.comhttps://www.learnfk.com/c++/cpp-multimap-non-member-operator>-function.html
来源:LearnFk无涯教程网
#include <iostream> #include <map> using namespace std; int main() { multimap<char, int> m1; multimap<char, int> m2; m1.emplace('a', 100); if (m1 > m2) cout << "Multimap m1 is greater than m2." << endl; m1 = m2; if (!(m1 > m2)) cout << "Multimap m1 is not greater than m2." << endl; return 0; }
输出:
Multimap m1 is greater than m2. Multimap m1 is not greater than m2.
在上面的示例中,有两个multimapm1和m2。 M1包含一个元素,而m2为空。当我们比较两个multimap时,它将显示消息"multimapm1大于m2",并且在将m2分配给m1之后,两个multimap具有相等的元素,然后它将显示消息"multimapm1不大于m2"。
让我们看一个简单的例子:
#include <map> #include <iostream> using namespace std; int main( ) { multimap < int, int > m1, m2, m3; int i; typedef pair < int, int > Int_Pair; for ( i = 0 ; i < 3 ; i++ ) { m1.insert ( Int_Pair ( i, i ) ); m2.insert ( Int_Pair ( i, i * i ) ); m3.insert ( Int_Pair ( i, i - 1 ) ); } if ( m1 > m2 ) cout << "The multimap m1 is greater than the multimap m2." << endl; else cout << "The multimap m1 is not greater than the multimap m2." << endl; if ( m1 > m3 ) cout << "The multimap m1 is greater than the multimap m3." << endl; else cout << "The multimap m1 is not greater than the multimap m3." << endl; return 0; }
输出:
The multimap m1 is not greater than the multimap m2. The multimap m1 is greater than the multimap m3.
让我们看一个简单的例子:
#include <iostream> #include <map> using namespace std; int main () { multimap < char , int > m1 , m2 ; m1.insert ( make_pair ( 'a' , 10 )); m1.insert ( make_pair ( 'b' , 20 ) ); m1.insert ( make_pair ( 'c' , 30 )); m2 = m1 ; cout << ( m1 < m2 ) << endl ; m2.insert ( make_pair ( 'd' , 40 )); cout << ( m1 < m2 ) << endl ; return 0 ; }
输出:
0 1
在上面的示例中,如果m1大于m2,则它将返回1,否则返回0。
#include <map> #include <iostream> using namespace std; int main () { multimap<int,string> m2; typedef multimap<int,string> login; m2.insert({2040, "xyz@123"}) ; //stored id and password string password; int id; login m1; cout<<"---------Login----------"<<endl<<endl; cout<<"Enter the ID and password: \n"; cin>> id; //Get key cin>> password; //Get value m1.insert({id, password}); //Put them in multimap cout<<"ID and password you have entered: \n"; for (auto it = m1.begin(); it != m1.end(); it++) { cout << (*it).first << " " << (*it).second << endl; } cout<<"ID and Password stored in the system :\n"; for (auto it = m2.begin(); it != m2.end(); it++) { cout << (*it).first << " " << (*it).second << endl; } if (m2 > m1) cout << "\nIncorrect ID or Password..." << endl; else cout << "\nWelcome to your Page..." << endl; return 0; }
输出:
1). ----------Login---------- Enter the ID and password: 1020 xyz ID and password you have entered: 1020 xyz ID and Password stored in the system: 2040 xyz@123 Incorrect ID or Password... 2). ----------------Login--------------- Enter the ID and password: 2040 xyz@123 ID and password you have entered: 2040 xyz@123 ID and Password stored in the system: 2040 xyz@123 Welcome to your Page...
在上面的示例中,有两个multimapm1和m2。 m1包含存储的ID和密码,第二个multimapm2存储用户输入的ID和密码。它检查m2是否大于m1。如果m2的ID和密码不大于m1,则登录成功,否则登录失败。
祝学习愉快!(内容编辑有误?请选中要编辑内容 -> 右键 -> 修改 -> 提交!)