Fruit Shop-Lanqiao Cup【STL】

Learning STL, this question is a mapping of str -> str -> int. If you are familiar with STL, it is easy to do, but if you don’t write it for a long time, you can forget about it. After seeing how someone else does it, I still feel that STL is strong and I am used to python. Just mess with C++ and write a bunch of bugs by myself.

Then we understand that it is the mapping relationship of str -> str -> int. Use map to store and open an iterator to iterate. Since auto is disabled, you can use iterator.

#include <bits/stdc++.h>
using namespace std;
int main()
{
  int n;
 	cin >> n;	
  map<string,map<string,int> > fruit;
  string type,place;
  int num;
  for(int i = 0; i < n; i ++){
    cin >> type >> place >> num;
    fruit[place][type] += num;
  }
  map<string,map<string,int> > :: iterator it;
  map<string,int> :: iterator ti;
  for(it = fruit.begin(); it != fruit.end(); it ++){
    cout << it -> first << endl;
    for (ti = it->second.begin(); ti != it->second.end(); ti ++){
      cout << "   |----" << ti->first << "(" << ti->second << ")" << endl;
    }
  }
  
  return 0;
}

The picture originated from Ji Suanke, invaded and deleted.