带权图模板

加权图DFS&BFS模板

最新推荐文章于 2023-09-09 01:30:53 发布

转载最新推荐文章于 2023-09-09 01:30:53 发布 · 112 阅读

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原文链接：http://www.cnblogs.com/tech-cabin/p/ForwardStar_Wight_Graph_Template.html

使用前向星方法（应该是吧？我着实不确定这种我不知道从哪看到之后一直在用的存储方法究竟叫什么= =）存储的带权图，实现了通用的DFS和BFS算法，可以通过函数对象使用。

正好这两天复习算法，所以整理了一下。有些时候有这么一个模板还是挺方便的说。。

直接上代码了

  1 struct ForwardStarWGraph;
  2 struct Node;
  3 
  4 struct CallbackFunctor
  5 {
  6     virtual bool shouldExtend(ForwardStarWGraph& graph, Node& toExtend) = 0;
  7     virtual bool operator() (ForwardStarWGraph& graph, Node& curr) = 0;
  8 };
  9 
 10 struct Node
 11 {
 12     int i;
 13     int from;
 14     int edge;
 15     int totalWight;
 16     vector<int> path;
 17 };
 18 
 19 const int N = 20; // max vertex conut
 20 const int M = N*N; // max edge count
 21 
 22 struct ForwardStarWGraph
 23 {
 24     int to[M], nxt[M], head[N];
 25     int wight[M];
 26     int ecnt;
 27     // Actual vertex number
 28     int n;
 29 
 30     void graphInit(int nn, int m)
 31     {
 32         ecnt = 0;
 33         n = nn;
 34         memset(head, -1, sizeof(head));
 35     }
 36 
 37     // Add an edge, vertex counts from 0
 38     void addEdge(int u, int v, int w)
 39     {
 40         to[ecnt] = v;
 41         wight[ecnt] = w;
 42         nxt[ecnt] = head[u];
 43         head[u] = ecnt;
 44         ecnt++;
 45     }
 46 
 47     // Add an undirectional edge
 48     void addBiEdge(int u, int v, int w)
 49     {
 50         addEdge(u, v, w);
 51         addEdge(v, u, w);
 52     }
 53 
 54     int wightBetween(int a, int b)
 55     {
 56         if(a == b)
 57             return 0;
 58         for(int e = head[a]; e!= -1; e = nxt[e])
 59         {
 60             if(to[e] == b)
 61                 return wight[e];
 62         }
 63         return -1;
 64     }
 65 
 66     void bfs(CallbackFunctor& func)
 67     {
 68         queue<Node> Q;
 69 
 70         Node tem;
 71         tem.i = 0;
 72         tem.from = -1;
 73         tem.edge = -1;
 74         tem.totalWight = 0;
 75         tem.path.push_back(0);
 76         Q.push(tem);
 77 
 78         while(!Q.empty())
 79         {
 80             Node t = Q.front(); Q.pop();
 81 
 82             func(*this, t);
 83 
 84             for(int e = head[t.i]; e!= -1; e = nxt[e])
 85             {
 86                 if(to[e] == t.from)
 87                     continue;
 88                 Node t2;
 89                 t2.i = to[e];
 90                 t2.from = t.i;
 91                 t2.edge = e;
 92                 t2.totalWight = t.totalWight + wight[e];
 93                 t2.path = t.path; t2.path.push_back(t2.i);
 94                 if(func.shouldExtend(*this, t2))
 95                 {
 96                     Q.push(t2);
 97                 }
 98             }
 99         }
100     }
101 
102     void dfs(CallbackFunctor& func)
103     {
104         stack<Node> Q;
105 
106         Node tem;
107         tem.i = 0;
108         tem.from = -1;
109         tem.edge = -1;
110         tem.totalWight = 0;
111         tem.path.push_back(0);
112         Q.push(tem);
113 
114         while(!Q.empty())
115         {
116             Node t = Q.top(); Q.pop();
117 
118             func(*this, t);
119 
120             for(int e = head[t.i]; e!= -1; e = nxt[e])
121             {
122                 if(to[e] == t.from)
123                     continue;
124                 Node t2;
125                 t2.i = to[e];
126                 t2.from = t.i;
127                 t2.edge = e;
128                 t2.totalWight = t.totalWight + wight[e];
129                 t2.path = t.path; t2.path.push_back(t2.i);
130                 if(func.shouldExtend(*this, t2))
131                 {
132                     Q.push(t2);
133                 }
134             }
135         }
136     }
137 };

View Code

附带一个测试小程序

 1 int n, m;
 2 ForwardStarWGraph g;
 3 
 4 struct Routine : CallbackFunctor
 5 {
 6     virtual bool shouldExtend (ForwardStarWGraph& graph, Node& toExtend)
 7     {
 8         return true;;
 9     }
10 
11     virtual bool operator() (ForwardStarWGraph& graph, Node& curr)
12     {
13         cout<<curr.i+1<<endl;
14     }
15 };
16 
17 int main()
18 {
19 #ifdef ACM_LOCAL
20     freopen("input.txt", "r", stdin);
21     //freopen("output.txt", "w", stdout);
22 #endif // ACM_LOCAL
23     while(scanf("%d %d", &n, &m) != EOF)
24     {
25         g.graphInit(n, m);
26         for(int i = 0; i!= m; i++)
27         {
28             int a, b, w;
29             scanf("%d%d%d", &a, &b, &w);
30             g.addBiEdge(a-1, b-1, w);
31         }
32         Routine routine;
33         g.bfs(routine);
34     }
35 
36 
37 #ifdef ACM_LOCAL
38     printf("Used time: %lf\n", clock() / (double) CLOCKS_PER_SEC);
39 #endif // ACM_LOCAL
40     return 0;
41 }

View Code

转载于:https://www.cnblogs.com/tech-cabin/p/ForwardStar_Wight_Graph_Template.html