COCR#1 T2-烦人の建交 题解

#include<bits/stdc++.h>
using namespace std;
int main() {
    int N;
    cin>>N;
    unordered_map<int,int>mint;
    long long sum=0;
    for (int i=0;i<N;++i) {
        int n,t;
        cin>>n>>t;
        auto it=mint.find(n);
        if(it==mint.end()){
            mint[n]=t;
            sum+=t;
        }
        else if(t<it->second){
            sum-=it->second;
            sum+=t;
            it->second=t;
        }
    }
    cout<<sum<<endl;
    return 0;
}