问题描述
根据，我正在尝试创建地图使用一对整数作为关键字 map< pair< int，int> int> ，我找到了如何插入信息：
Based on a previous question, I am trying to create a map using a pair of integers as a key i.e. map<pair<int, int>, int> and I've found information on how to insert:
#include <iostream>
#include <map>
using namespace std;
int main ()
{
map<pair<int, int>, int> mymap;
mymap.insert(make_pair(make_pair(1,2), 3)); //edited
}
但我似乎无法访问元素！我试过 cout<< mymap [（1,2）]< endl; 但它显示一个错误，我找不到如何使用键访问元素的信息。
but I can't seem to access the element! I've tried cout << mymap[(1,2)] << endl; but it shows an error, and I can't find information on how to access the element using the key. Am I doing something wrong?
推荐答案
您需要一个键作为键 cout< mymap [make_pair（1,2）]< endl; 您目前拥有的 cout<< mymap [（1,2）]< endl; 不是正确的语法。
you need a pair as a key cout << mymap[make_pair(1,2)] << endl; What you currently have cout << mymap[(1,2)] << endl; is not the correct syntax.
这篇关于使用pair< int，int>作为地图的关键的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！