华为笔试：N度好友

#include <bits/stdc++.h>
using namespace std;

bool cmp(pair<int,int> a, pair<int,int> b){
    if(a.second > b.second) return 1;
    if(a.second==b.second) return a.first < b.first;
    return 0;
}

int main(){
    int t;
    cin>>t;
    while(t--){
        int m,i,n;
        cin>>m>>i>>n;
        int k;
        cin>>k;
        
        vector<vector<int> > graph( m, vector<int>(m,0) );
        int ki,kj,kw;
        for(int i=0; i<k; i++){
            cin>>ki>>kj>>kw;
            graph[ki][kj] = kw;
            graph[kj][ki] = kw;
        }
        
        vector<bool> visited(m,0); 
        vector<int> friendly(m,-1);
        queue<int> temp;
        temp.push(i);
        while(!temp.empty() ){
            int size = temp.size();
            while(size--){
                int cur = temp.front();
                temp.pop();
                visited[cur] = 1;
                for(int x=0; x<m; x++){
                    if( !visited[x] && graph[cur][x] > 0 && friendly[x]==-1 ){
                        friendly[x] = friendly[cur] + graph[cur][x];
                        temp.push(x);
                    }                     
                }            
            }
            
            n--;
            if(n==0) break;
        }
        
        if(n!=0 || temp.empty()){
            cout<<-1<<endl;
            continue;
        }
        
        vector<pair<int,int> > res;
        
        map<int,int> exist;
        while(!temp.empty()){
            exist[ temp.front() ]  = friendly[ temp.front() ];
            temp.pop();         
        } 
        res.assign(exist.begin(), exist.end() );
        
        sort(res.begin(), res.end(), cmp);
        for(int p=0;p<res.size(); p++){
            cout<<res[p].first<<" "; 
        }
        cout<<endl;
        
    }
    
}