字符串索引图，使用了map映射，用了一些不常用的知识，能这么写出来很开心
这么写可以使得map的默认值为INF而不是值初始化的0
struct defaultCost{
int cost;
defaultCost():cost(INF){
}; // 更改不存在key的map的默认value值为INF
defaultCost(int c):cost(c){
}
};
map<string, defaultCost> cost; // 之前的dist数组，改名了
当点的编号不是数字而是字符串的时候使用map是个不错的方法
map<string, vector<Node> > G; // 边权
map<string, int> V; // 点权
map<string, defaultCost> cost; // 之前的dist数组，改名了
map<string, bool> vis;
map<string, vector<string>> pre;
Dijkstra + DFS
# include <iostream>
# include <algorithm>
# include <vector>
# include <map>
using namespace std;
const int MAXV = 210;
const int INF = 0xffffff;
struct Node{
string name;
int cost;
};
// 设一个结构体并赋予初值就可以设定访问map不存在的key时的默认value值
struct defaultCost{
int cost;
defaultCost():cost(INF){
}; // 更改不存在key的map的默认value值为INF
defaultCost(int c):cost(c){
}
};
map<string, vector<Node> > G; // 边权
map<string, int> V; // 点权
map<string, defaultCost> cost; // 之前的dist数组，改名了
map<string, bool> vis;
map<string, vector<string>> pre;
int N, K;
string st, ed = "ROM";
void Dijsktra(string s){
cost[s] = 0;
for(int i = 0;i < N;++i){
string u = "000";
int MIN = INF;
for(auto p: V){
string j = p.first;
if(vis[j] == false && cost[j].cost < MIN){
u = j;
MIN = cost[j].cost;
}
}
if(u == "000") return;
vis[u] = true;
for(Node next: G[u]){
string v = next.name;
int uv_cost = next.cost;
if(vis[v] == false){
if(cost[u].cost + uv_cost < cost[v].cost){
cost[v].cost = cost[u].cost + uv_cost;
pre[v].clear();
pre[v].push_back(u);
}
else
if(cost[u].cost + uv_cost == cost[v].cost){
pre[v].push_back(u);
}
}
}
}
}
vector<string> path, tempPath;
int routes = 0; // 相等cost的路径数量
int maxSumHappyness = -1; // 最大快乐值;
double maxAvgHappyness = -1; // 最大平均快乐值
void DFS(string v){
if(v == st){
routes++;
tempPath.push_back(st);
int sumhappyness = 0;
double avghappyness = 0.0;
for(string id: tempPath){
sumhappyness += V[id];
}
avghappyness = sumhappyness / (tempPath.size() - 1);
if(sumhappyness > maxSumHappyness){
maxSumHappyness = sumhappyness;
maxAvgHappyness = avghappyness;
path = tempPath;
}
else
if(sumhappyness == maxSumHappyness){
if(avghappyness > maxAvgHappyness){
maxAvgHappyness = avghappyness;
path = tempPath;
}
}
tempPath.pop_back();
return;
}
tempPath.push_back(v);
for(string u: pre[v]){
DFS(u);
}
tempPath.pop_back();
}
int main(){
cin >> N >> K >> st;
for(int i = 0;i < N-1;++i){
// 不输入起点的开心值，所以要N-1，并且给起点得到开心值初始化为0（被坑了）
string city;
int happy;
cin >> city >> happy;
V[city] = happy;
}V[st] = 0;
for(int i = 0;i < K;++i){
string city1, city2;
int cost;
cin >> city1 >> city2 >> cost;
G[city1].push_back({
city2, cost});
G[city2].push_back({
city1, cost});
}
Dijsktra(st);
DFS(ed);
printf("%d %d %d %.0f\n",routes, cost[ed].cost, maxSumHappyness, maxAvgHappyness);
for(int i = path.size() - 1;i >= 0;--i){
cout << path[i];
if(i != 0)
cout << "->";
else
cout << "\n";
}
return 0;
}