图论粗略笔记 

 1 void dfs(int x){
 2     vis[x] = 1;
 3     printf("%d\n",x);
 4     for(ont i = head[x];i;i = nst[i]) if(!vis[to[i]]) dfs(to[i]);
 5 }
 6 
 7 void bfs(int x){
 8     z[++top] = x;
 9     for(int i = 1;i<=top;i++){
10         int now = z[top++];
11         printf("%d\n",now);
12         for(itn j = head[now];j;j = nxt[j])
13         if(!vis[to[j]]) vis[to[j]] = 1,z[++top] = to[j];
14     }
15 }
16 //图的遍历
17 void spfa(){
18     memeset(dis,0x3f,sizeof(dis));
19     dis[s] = 0;
20     z[top = 1] = s;
21     for(int j = 1;j<=top;j++){
22         int now = z[j];
23         vis[now] = 0;
24         for(int i = head[now];i;i = nxt[i]){
25             if(dis[to[i]]>dis[now] + w[i]){
26                 dis[to[i]] = dis[now] + w[i];
27                 if(!vis[to[i]]) vis[to[i]] = 1,z[++top] = to[i];
28             }
29         }
30     }
31     return;
32 } 
33 //SPFA单源最短路 每次从队列中取出队首点，更新与其相连的点的dis
34 
35 for(int k = 1;k<=n;k++){
36     for(int i = 1;i<=n;i++){
37         for(int j = 1;j<=n;j++){
38             f[i][j] = min(f[i][j],f[i][k]+f[k][j]);
39         }
40     } 
41 } 
42 //FLOYD 多源最短路
43 
44 struct node{
45     int id,dis;
46     friend bool operator < (node x,node y){
47         return x.dis>y.dis;
48     }
49 }; 
50 priority_queue<node>q;
51 
52 memset(dis,0x3f,sizeof(dis));
53 dis[1] = 0;
54 q.push({0,0});
55 while(!q.empty()){
56     now = (q.top()).id;
57     q.pop();
58     if(vis[now]) continue;
59     vis[now] = 1;
60     for(int i = head[now];i;i = nxt[i]){
61         if(dis[to[i]]>dis[now] + w[i]){
62             dis[to[i]] = dis[now] + w[i];
63             q.push({to[i],dis[to[i]]});
64         }
65     }    
66 }
67 
68 //Dijkstra算法

 

posted @ 2022-02-11 08:55  November&&Rain  阅读(40)  评论(0)    收藏  举报