map的使用

二维map 的使用

#include <iostream>
#include <map>
using namespace std;
map<string, map<string, int> > dict;
int main(){
    int n;
    cin>>n;
    for (int i = 0; i < n; i++) {
        int num;
        string cd, mc;
        cin>>mc>>cd>>num;
		dict[cd][mc] += num;
    }
	for(auto it=dict.begin();it!=dict.end();it++){
		cout<<it->first<<endl;
		for(auto is=(it->second).begin();is!=(it->second).end();is++){
			cout<<"   |----"<<is->first<<"("<<is->second<<")"<<endl;
		}
	}
    return 0;
}

测试：
5
apple shandong 3
pineapple guangdong 1
sugarcane guangdong 1
pineapple guangdong 3
pineapple guangdong 1
结果：
guangdong
|----pineapple(5)
|----sugarcane(1)
shandong
|----apple(3)