1030 Travel Plan (30分) dij模板题

题目

https://pintia.cn/problem-sets/994805342720868352/problems/994805464397627392

题意

~~

Sample Input:

4 5 0 3
0 1 1 20
1 3 2 30
0 3 4 10
0 2 2 20
2 3 1 20

Sample Output:

0 2 3 3 40

code

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int N,M,S,D;
struct node{
    int d,c,num;
}city[505];
struct edge{
    int v,d,c;
    edge(int a,int b,int c1):v(a),d(b),c(c1){}
};
vector<edge>G[505];
bool operator < (const node x,const node y) {return x.d>y.d;}
bool visit[505];
int fa[505];
void dij()
{
    for(int i=0;i<N;++i) {
        city[i].num=i;
        city[i].c=(i==S?0:INT_MAX);
        city[i].d=(i==S?0:INT_MAX);
    }
    priority_queue<node>Q;
    Q.push(city[S]);
    while(!Q.empty())
    {
        node t=Q.top(); Q.pop();
        if(visit[t.num]) continue;
        else visit[t.num]=1;

        int u=t.num;
        for(int i=0;i<G[u].size();++i)
        {
            int v=G[u][i].v;
            int dis=G[u][i].d;
            int cost=G[u][i].c;
            if(city[v].d>city[u].d+dis ||
               (city[v].d==city[u].d+dis && city[v].c>city[u].c+cost))
           {
               city[v].d=city[u].d+dis;
               city[v].c=city[u].c+cost;
               fa[v]=u;
               Q.push(city[v]);
           }
        }
    }
}

void path()
{
    stack<int>st;
    int p=D;
    while(p!=S)
    {
        st.push(p);
        p=fa[p];
    }
    cout<<S;
    while(!st.empty()){
        cout<<" "<<st.top();
        st.pop();
    }
}

int main()
{
    cin>>N>>M>>S>>D;
    for(int i=1;i<=M;++i)
    {
        int a,b,c,d; cin>>a>>b>>c>>d;
        G[a].push_back(edge(b,c,d));
        G[b].push_back(edge(a,c,d));
    }
    dij();
    path();
    cout<<" "<<city[D].d<<" "<<city[D].c<<endl;
    return 0;