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Dijkstra搜最短路,再dfs查费用最少的一条。模板题。
#include<iostream>
#include<cstdlib>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<climits>
using namespace std;
int INF = INT_MAX;
int n,m,s,d;
struct Edge{
int next, dis, cost;
Edge(){}
Edge(int next, int dis, int cost) : next(next), dis(dis), cost(cost){}
};
vector<Edge> graph[505];
int dis[505];
int vis[505];
int min_distance;
void Dijkstra(){
for(int i = 0; i < n; ++i){
dis[i] = INF;
vis[i] = 0;
}
dis[s] = 0;
vis[s] = 1;
for(int i = 0; i < graph[s].size(); ++i){
dis[graph[s][i].next] = graph[s][i].dis;
}
int v, min_dis;
while(1){
min_dis = INF;
v = -1;
for(int i = 0; i < n; ++i){
if(!vis[i] && min_dis > dis[i]){
min_dis = dis[i];
v = i;
}
}
if(v == -1) break;
vis[v] = 1;
for(int i = 0; i < graph[v].size(); ++i){
if(!vis[graph[v][i].next] && dis[v] + graph[v][i].dis < dis[graph[v][i].next]){
dis[graph[v][i].next] = dis[v] + graph[v][i].dis;
}
}
}
}
int min_cost = INF;
vector<int> final_path;
void dfs(int cur, int cost, int road, vector<int> path){
if(road > min_distance) return;
if(cur == d) {
if(cost < min_cost){
final_path = path;
min_cost = cost;
}
return;
}
int mark;
for(int i = 0; i < graph[cur].size(); ++i){
if(!vis[graph[cur][i].next]){
vis[graph[cur][i].next] = 1;
path.push_back(graph[cur][i].next);
dfs(graph[cur][i].next, cost + graph[cur][i].cost, road + graph[cur][i].dis,path);
vis[graph[cur][i].next] = 0;
path.pop_back();
}
}
}
int main(){
scanf("%d%d%d%d",&n,&m,&s,&d);
int a,b,dist,cost;
for(int i = 0; i < m; ++i){
scanf("%d%d%d%d",&a,&b,&dist,&cost);
graph[a].push_back(Edge(b,dist,cost));
graph[b].push_back(Edge(a,dist,cost));
}
Dijkstra();
min_distance = dis[d];
for(int i = 0; i < n; ++i) vis[i] = 0;
vector<int> tmp_path;
tmp_path.push_back(s);
dfs(s,0,0,tmp_path);
for(int i = 0; i < final_path.size(); ++i){
cout << final_path[i] << " ";
}
cout << dis[d] << " " << min_cost << endl;
return 0;
}