cf 20C Dijkstra?

带队列  dijkstra

 1 #include <iostream>
 2 #include <cstdio>
 3 #include <queue>
 4 #include <vector>
 5 #include<memory.h>
 6 #include<algorithm>//reverse
 7 using namespace std;
 8 #define maxn 100002
 9 #define INF 65
10 struct node
11 {
12     int u;
13     int w;
14     node(long long x,long long y)
15     {
16         u = x;
17         w = y;
18     }
19     bool operator < ( const node& p ) const
20     {      return w > p.w;   }
21 };
22 vector<long long>g[maxn];
23 vector<long long>cost[maxn];
24 long long d[maxn];
25 long long par[maxn];
26 int dijk(int n)
27 {
28     memset(d, INF, sizeof(d));
29     memset(par, -1, sizeof(par));
30     priority_queue<node>q;
31     q.push(node(1,0));
32     d[1]=0;
33     while(!q.empty())
34     {
35         node top = q.top();
36         q.pop();
37         int uu = top.u;
38         if(uu == n) return d[n];
39         for(int i = 0;i < g[uu].size(); i++)
40         {
41             int v = g[uu][i];
42             if(d[uu] + cost[uu][i] < d[v])
43             {
44                 d[v] = d[uu] + cost[uu][i];
45                 par[v] = uu;
46                 q.push(node(v,d[v]));
47             }
48         }
49     }
50     return -1;
51 }
52 int main()
53 {
54     //freopen("input.txt","r",stdin);
55     int n,e,u,v;
56     long long w;
57     cin>>n>>e;
58     for(int i = 0; i < e; i++)
59     {
60         cin>>u>>v>>w;
61         g[u].push_back(v);cost[u].push_back(w);
62         g[v].push_back(u);cost[v].push_back(w);
63
64     }
65     w = dijk(n);
66     if(w == -1) cout<<"-1"<<endl;
67     else
68     {
69         int t = n;
70         int s[maxn];
71         int k = 0;
72         while(t != -1)
73         {
74             s[k++] = t;
75             t = par[t];
76         }
77         for(int j = k - 1; j >= 0; j--)
78             cout<<s[j]<<" ";
79         cout<<endl;
80     }
81 }

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