题解 | 小红背单词

#include <iostream>
#include<unordered_map>
#include<unordered_set>
using namespace std;

int main() {
   int n;
   cin>>n;
   unordered_map<string,int> vocs;
   unordered_set<string> remembered; 
   int need=1;
   int count=0;
   while(n--){
       string voc;
       cin>>voc;
       if(remembered.find(voc)!=remembered.end()){
        continue;
       }
       vocs[voc]++;
       if(vocs[voc]==need){
        count++;
        need++;
        remembered.insert(voc);
       }
   }
   cout<<count<<endl;
   return 0;
}