C++中的哈希容器unordered_map使用示例

#include <iostream>
#include <string>
#include <unordered_map>
 
int main()
{
 std::unordered_map<std::string, int> months;
 months["january"] = 31;
 months["february"] = 28;
 months["march"] = 31;
 months["april"] = 30;
 months["may"] = 31;
 months["june"] = 30;
 months["july"] = 31;
 months["august"] = 31;
 months["september"] = 30;
 months["october"] = 31;
 months["november"] = 30;
 months["december"] = 31;
 std::cout << "september -> " << months["september"] << std::endl;
 std::cout << "april   -> " << months["april"] << std::endl;
 std::cout << "december -> " << months["december"] << std::endl;
 std::cout << "february -> " << months["february"] << std::endl;
 return 0;
}