1035 head of a gang

简单并查集

AC代码

#include <map>
#include <string>
#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
string find(map<string,string>& r,string n){
    while(n != r[n]){
        n = r[n];
    }
    return n;
}
void unit(map<string,string>& r,map<string,int>& t,string n1,string n2){
    string s1(find(r,n1)),s2(find(r,n2));
    if(t[s1] < t[s2])
        r[s1] = s2;
    else if(t[s2] < t[s1])
        r[s2] = s1;
    else if(s2 < s1)
        r[s1] = r[s2];
    else
        r[s2] = r[s1];
}
int main(){
    int n,k;
    scanf("%d %d",&n,&k);
    map<string,string> r;
    map<string,int> t;
    map<string,bool> vs;
    vector<pair<string,string>> rini;
    for(int i = 0;i < n;i++){
        string n1,n2;
        int tc;
        cin >> n1 >> n2 >> tc;
        vs[n1] = vs[n2] = false;
        pair<string,string> p;
        p.first = n1;
        p.second = n2;
        rini.push_back(p);
        t[n1] += tc;
        t[n2] += tc;
        r[n1] = n1;
        r[n2] = n2;
    }
    for(int i = 0;i < n;i++){
        unit(r,t,rini[i].first,rini[i].second);
    }
    int count(0);
    map<string,int> gt;
    map<string,int> gn;
    for(map<string,string>::iterator ite = r.begin();ite != r.end();ite++){
        gn[find(r,ite->first)]++;
        gt[find(r,ite->first)] += t[ite->first];
    }
    for(map<string,int>::iterator ite = gt.begin();ite != gt.end();ite++){
        if(ite->second <= 2 * k || gn[ite->first] <= 2)
            gn.erase(ite->first);
    }
    printf("%d
",gn.size());
    for(map<string,int>::iterator ite = gn.begin();ite != gn.end();ite++){
        printf("%s %d
",ite->first.c_str(),ite->second);
    }
    return 0;
}