C++map容器-大小和互換
阿新 • • 發佈:2021-02-19
map大小和互換
功能描述:
統計map容器大小以及交換map容器
函式原型:
程式碼如下:
#include <iostream>
using namespace std;
#include <map>
//map容器 大小和交換
void test01() {
map<int, int>m;
m.insert(pair<int, int>(1, 10));
m.insert(pair<int, int>(2, 20));
m.insert(pair<int, int> (3, 30));
if (m.empty()) {
cout << "m為空" << endl;
} else {
cout << "m不為空" << endl;
cout << "m的大小為:" << m.size() << endl;
}
}
void printMap(map<int, int> &m) {
for (map<int, int>::iterator it = m.begin (); it != m.end(); it++) {
cout << "key = " << it->first << " " << "value = " << it->second << endl;
}
cout << endl;
}
void test02() {
map<int, int>m1;
m1.insert(pair<int, int>(1, 10));
m1.insert(pair< int, int>(2, 20));
m1.insert(pair<int, int>(3, 30));
map<int, int>m2;
m2.insert(pair<int, int>(4, 100));
m2.insert(pair<int, int>(5, 200));
m2.insert(pair<int, int>(6, 300));
cout << "交換前:" << endl;
printMap(m1);
printMap(m2);
cout << "交換後:" << endl;
m1.swap(m2);
printMap(m1);
printMap(m2);
}
int main() {
test01();
cout << "----------------------" << endl;
test02();
return 0;
}