public DepthFirstSearch(GraphUndirected g, int s)
{
// 初始化 markeds的数组
this.markeds = new bool[g.countV()];
// 初始跟顶点s相通的顶点的数量
this.countNum = 0;
dfs(g, s);
}
public DepthFirstPaths(GraphUndirected g, int s)
{
// 初始化 markeds数组
this.markeds = new bool[g.countV()];
// 初始化起点
this.s = s;
this.edgeTo = new int[g.countV()];
dfs(g, s);
}
public BreadthFirstSearch(GraphUndirected g, int s)
{
// 初始化 markeds的数组
this.markeds = new bool[g.countV()];
// 初始跟顶点s相通的顶点的数量
this.countNum = 0;
this.waitSearch = new QueueList <int>();
bfs(g, s);
}
/// <summary>
/// 使用深度优先搜索找到g图中v顶点的所有相遇顶点
/// </summary>
/// <param name="g"></param>
/// <param name="v"></param>
private void dfs(GraphUndirected g, int v)
{
// 把v顶点的 marked标为true
this.markeds[v] = true;
IEnumerator ie = g.adjGet(v).GetEnumerator();
while (ie.MoveNext())
{
int w = (int)ie.Current;
if (!this.markeds[w])
{
dfs(g, w);
}
}
// 相通顶点数量 +1
this.countNum++;
}
private void dfs(GraphUndirected g, int v)
{
this.markeds[v] = true;
// 遍历顶点v的邻接表，拿到每一个相邻的顶点继续递归
IEnumerator ie = g.adjGet(v).GetEnumerator();
while (ie.MoveNext())
{
int w = (int)ie.Current;
// 如果顶点我没有被搜索，递归搜索
if (!this.markeds[w])
{
// 到达顶点w的路径上的最后一个顶点是v
edgeTo[w] = v;
dfs(g, w);
}
}
}
/// <summary>
/// 判断 路是否相通
/// </summary>
private static void GraphRoad()
{
GraphUndirected graph = new GraphUndirected(20);
// 已经修好的路 7条 0-1 6-9 3-8 5-11 2-12 6-10 4-8
Dictionary <int, int> hadRoad = new Dictionary <int, int>();
hadRoad.Add(0, 1);
hadRoad.Add(6, 9);
hadRoad.Add(3, 8);
hadRoad.Add(5, 11);
hadRoad.Add(2, 12);
hadRoad.Add(4, 8);
foreach (KeyValuePair <int, int> item in hadRoad)
{
// 调用并查集对象的 union方法让两个城市相交
graph.addEdge(item.Key, item.Value);
}
graph.addEdge(6, 10);
// 调用marked方法判断8顶点、10顶点是否和9顶点相遇
// 设置顶点 point 为 9
int point = 9;
DepthFirstSearch dSearch = new DepthFirstSearch(graph, point);
bool markD1 = dSearch.marked(8);
bool markD2 = dSearch.marked(10);
Console.WriteLine(string.Format("Depth mark1: {0}, mark2: {1}", markD1, markD2));
BreadthFirstSearch bSearch = new BreadthFirstSearch(graph, point);
bool markB1 = bSearch.marked(8);
bool markB2 = bSearch.marked(10);
Console.WriteLine(string.Format("Breadth mark1: {0}, mark2: {1}", markB1, markB2));
}
/// <summary>
/// 使用广度优先搜索找到g图中v顶点的所有相遇顶点
/// </summary>
/// <param name="g"></param>
/// <param name="v"></param>
private void bfs(GraphUndirected g, int v)
{
// 把v顶点的 marked标为true
this.markeds[v] = true;
// 把顶点v进入队列，待搜索
this.waitSearch.enqueue(v);
// 通过循环 如果队列不为空，则从队列中弹出一个待搜索的顶点进行搜索
while (!this.waitSearch.isEmpty())
{
int wait = this.waitSearch.dequeue();
IEnumerator ie = g.adjGet(wait).GetEnumerator();
while (ie.MoveNext())
{
int w = (int)ie.Current;
if (!this.markeds[w])
{
bfs(g, w);
}
}
}
// 相通顶点数量 +1
this.countNum++;
}
/// <summary>
/// 广度优先搜索
/// </summary>
private static void BreadthFirstSearchTest()
{
// 准备 graph 对象
GraphUndirected graph = new GraphUndirected(13);
graph.addEdge(0, 5);
graph.addEdge(0, 1);
graph.addEdge(0, 2);
graph.addEdge(0, 6);
graph.addEdge(5, 3);
graph.addEdge(5, 4);
graph.addEdge(3, 4);
graph.addEdge(4, 6);
graph.addEdge(7, 8);
graph.addEdge(9, 11);
graph.addEdge(9, 10);
graph.addEdge(9, 12);
graph.addEdge(11, 12);
// 准备深度优先搜索对象
int startPoint = 0;
BreadthFirstSearch search = new BreadthFirstSearch(graph, startPoint);
// 测试于某个顶点相遇的顶点数量
int count = search.count();
Console.WriteLine("start " + startPoint + " link count: " + count);
// 测试某个顶点是否与 startPoint 相通
bool marked = search.marked(5);
Console.WriteLine("start " + startPoint + " and " + 5 + " marked: " + marked);
bool marked2 = search.marked(7);
Console.WriteLine("start " + startPoint + " and " + 7 + " marked: " + marked2);
}
/// <summary>
/// 深度优先 的路径查询
/// </summary>
private static void DepthFirstPaths()
{
// 构建图
GraphUndirected graph = new GraphUndirected(6);
graph.addEdge(0, 2);
graph.addEdge(0, 1);
graph.addEdge(2, 1);
graph.addEdge(2, 3);
graph.addEdge(2, 4);
graph.addEdge(3, 5);
graph.addEdge(3, 4);
graph.addEdge(0, 5);
int s = 0;
DepthFirstPaths path = new DepthFirstPaths(graph, s);
int endW = 4;
StackList <int> stack = path.pathTo(endW);
//while (true)
//{
// if (stack.isEmpty())
// {
// break;
// }
// int p = stack.pop();
// Console.Write(p + ",");
//}
Console.WriteLine();
IEnumerator ie = stack.GetEnumerator();
while (ie.MoveNext())
{
int point = (int)ie.Current;
Console.Write(point + ",");
}
}
