1087. All Roads Lead to Rome (30) PAT 甲级

#include<stdio.h>
#include<iostream>
#include<vector>
#include<queue>
#include<string.h>
#include<algorithm>
#include<map>
#include<string>
using namespace std;

#define MAX_V 220
#define INF 1000000000

int G[MAX_V][MAX_V];
bool visited[MAX_V];
int happy[MAX_V];
int maxHappy=0;
int maxHappyAvg=0;
int n,m;
vector<int> pre[MAX_V];
vector<int> temp,path;
string s_name;
int d[MAX_V];
int num;
map<string,int> NameToId;
map<int,string> IdToName;

void Dijkstra(int s){
fill(d,d+MAX_V,INF);
d[s]=0;
for(int i=0;i<n;i++){
int u=-1,Min=INF;
for(int j=0;j<n;j++){
if(!visited[j]&&d[j]<Min){
u=j;
Min=d[j];
}
}
if(u==-1)   return;
visited[u]=true;
for(int v=0;v<n;v++){
if(!visited[v]&&G[u][v]!=INF){
if(d[u]+G[u][v]<d[v]){
d[v]=d[u]+G[u][v];
pre[v].clear();
pre[v].push_back(u);
}
else{
if(d[u]+G[u][v]==d[v]){
pre[v].push_back(u);
}
}
}
}
}
}

void DFS(int v){
if(v==0){
temp.push_back(v);
num++;
int tempH=0;
for(int i=temp.size()-2;i>=0;i--){
int vertex=temp[i];
tempH+=happy[vertex];
}
double tempHappyAvg=1.0*tempH/(temp.size()-1);
if(tempH>maxHappy){
path=temp;
maxHappy=tempH;
maxHappyAvg=tempHappyAvg;

}
else{
if(tempH==maxHappy&&tempHappyAvg>maxHappyAvg){
path=temp;
maxHappyAvg=tempHappyAvg;
}
}
temp.pop_back();
return;
}
temp.push_back(v);
for(int i=0;i<pre[v].size();i++){
DFS(pre[v][i]);
}
temp.pop_back();
}

int main(){
cin>>n>>m>>s_name;
string city,city1,city2;
NameToId[s_name]=0;
IdToName[0]=s_name;

for(int i=1;i<=n-1;i++){
cin>>city>>happy[i];
NameToId[city]=i;
IdToName[i]=city;
}
fill(G[0],G[0]+MAX_V*MAX_V,INF);
for(int i=0;i<m;i++){
cin>>city1>>city2;
int u=NameToId[city1],v=NameToId[city2];
cin>>G[u][v];
G[v][u]=G[u][v];
}
Dijkstra(0);
int rome=NameToId["ROM"];
DFS(rome);
printf("%d %d %d %d\n",num,d[rome],maxHappy,(int)maxHappyAvg);
for(int i=path.size()-1;i>=0;i--){
cout<<IdToName[path[i]];
if(i>0) cout<<"->";
}
}