public LazyPrimMST(WeightSpareGraph <float> g)
{
this.g = g;
this.n = g.V();
this.m = g.E();
minHeap = new MinHeap <Edge <float> > (m);
minSpanTreeEdge = new List <Edge <float> > ();
book = new bool[n];
for (int i = 0; i != n; i++)
{
book [i] = false;
}
book [0] = true;
visit(0);
while (minHeap.Size() != 0)
{
Edge <float> e = minHeap.ExtraMinItem();
int u = e.U();
int v = e.V();
if (book [u] == book [v])
{
continue;
}
if (!book [u])
{
book [u] = true;
minSpanTreeEdge.Add(e);
visit(u);
}
else
{
book [v] = true;
visit(v);
minSpanTreeEdge.Add(e);
}
// if (!book [e.V ()] && book [e.U ()]) {//这里出错了~~~= =other也出错了。。。
// book [e.V ()] = true;
// visit (e.V ());
// minSpanTreeEdge.Add (e);
// minSpanValue =minSpanValue+ e.weight;
// } else if (book [e.V ()] && !book [e.U ()]) {
// book [e.U ()] = true;
// visit (e.U ());
// minSpanTreeEdge.Add (e);
// minSpanValue += e.weight;
// } else if (book [e.V ()] && book [e.U ()]) {
// continue;
// } else {
// Debug.Assert (false);
// }
}
foreach (Edge <float> e in minSpanTreeEdge)
{
minSpanValue += e.weight;
}
}
// Use this for initialization
void Start()
{
//利用LazyPrim算法计算稀疏有权图的最短路径
print("求稀疏有权图的最小生成树");
string name = "";
string url = "";
name = "testWeightG1.txt";
url = FileHelper.FileNameHelper(name);
WeightSpareGraph <float> wsGraph = null;
ReadWeightGraph.ReadGraphFromFile(url, out wsGraph, false);
wsGraph.print();
LazyPrimMST lazyPrim = new LazyPrimMST(wsGraph);
lazyPrim.print();
print("最小生成树的长度为：" + lazyPrim.length());
print("使用深度优先搜索的方法得到一棵生成树");
lazyPrim = new LazyPrimMST(wsGraph, true);
lazyPrim.printOneTree();
print("*********************");
//利用Prim算法计算稀疏有权图的最短路径
PrimMST prim = new PrimMST(wsGraph);
prim.print();
}
public void visit(int u)
{
WeightSpareGraph <float> .adjIterator iter = new WeightSpareGraph <float> .adjIterator(graph, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
if (book [e.Other(u)])
{
continue;
}
int v = e.Other(u); // u
if (toEdgeArr [v] == null)
{
toEdgeArr [v] = e;
indexMinHeap.Insert(v, e.weight);
}
else
{
if (toEdgeArr [v].CompareTo(e) > 0)
{
toEdgeArr [v] = e;
indexMinHeap.Change(v, e.weight);
}
}
}
}
// Use this for initialization
void Start()
{
string name = "testWeightG1.txt";
string url = FileHelper.FileNameHelper(name);
WeightSpareGraph <float> sGraph = null;
ReadWeightGraph.ReadGraphFromFile(url, out sGraph, false);
KrusalMST <float> krusalMST = new KrusalMST <float> (sGraph);
print("Krusal算法生成的最小生成树,长度为" + krusalMST.length());
krusalMST.print();
}
//访问n节点,将所有的横切边加入最小索引堆
private void visit(int u)
{
WeightSpareGraph <float> .adjIterator iter = new WeightSpareGraph <float> .adjIterator(g, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
if (book [e.Other(u)] == true)
{
continue;
}
minHeap.Insert(e);
}
}
public Dijkstra(WeightSpareGraph <float> graph, int src)
{
Debug.Assert(src >= 0 && src < graph.V());
this.src = src;
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
shortPath = new float[n];
book = new bool[n];
from = new int[n];
for (int i = 0; i != n; i++)
{
book [i] = false;
from [i] = -1; //假设都是可达的
}
from [src] = -1;
shortPath [src] = 0f;
IndexMinHeap <float> indexMinHeap = new IndexMinHeap <float> (n);
indexMinHeap.Insert(src, shortPath[src]);
while (indexMinHeap.Size() != 0)
{
int u = indexMinHeap.ExtraMinItemIndex();
book [u] = true;
WeightSpareGraph <float> .adjIterator iter = new WeightSpareGraph <float> .adjIterator(graph, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
int v = e.Other(u);
if (!book[v])
{
if (from [v] == -1 || shortPath [v] > shortPath [u] + e.weight)
{
from [v] = u;
shortPath [v] = shortPath [u] + e.weight;
if (indexMinHeap.isContain(v))
{
indexMinHeap.Change(v, shortPath [v]);
}
else
{
indexMinHeap.Insert(v, shortPath[v]);
}
}
}
}
}
}
private void DSF(int u)
{
WeightSpareGraph <float> .adjIterator iter = new WeightSpareGraph <float> .adjIterator(g, u);
for (Edge <float> edge = iter.begin(); !iter.isEnd(); edge = iter.Next())
{
if (book [edge.Other(u)] == false)
{
book [edge.Other(u)] = true;
oneSpantreeEdge.Add(edge);
oneSpanValue += edge.weight;
DSF(edge.Other(u));
}
}
}
// Use this for initialization
void Start()
{
string name = "testWeightG1.txt";
// name = "testShortPath.txt";
string url = FileHelper.FileNameHelper(name);
WeightSpareGraph <float> sGraph = null;
ReadWeightGraph.ReadGraphFromFile(url, out sGraph, false);
sGraph.print();
Dijkstra dijkstra = new Dijkstra(sGraph, 0);
dijkstra.ShowAllPath();
BellmanFord bellmanFord = new BellmanFord(sGraph, 0);
bellmanFord.showAllPath();
}
private bool detectNegetiveCircle()
{
for (int u = 0; u != n; u++)
{
WeightSpareGraph <float> .adjIterator iter =
new WeightSpareGraph <float> .adjIterator(graph, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
//
int v = e.Other(u);
if (from [v] == -1 || shortPathValue [v] > shortPathValue [u] + e.weight)
{
return(false);
}
}
}
return(true);
}
public static void ReadGraphFromFile(string fileName, out WeightSpareGraph <float> graph, bool isDirected)
{
int V, E;
string[] strs = File.ReadAllLines(fileName);
Debug.Assert(strs.Length >= 2);
string veline = strs [0];
readGraphFileVELine(veline, out V, out E);
// Debug.Log ("V , E " + V +"," + E);
graph = new WeightSpareGraph <float>(V, isDirected);
for (int i = 0; i != E; i++)
{
string line = strs [i + 1];
int p, q;
float w;
readGraphFileVEWLine(line, out p, out q, out w);
graph.AddEdge(p, q, w);
}
}
public PrimMST(WeightSpareGraph <float> graph)
{
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
minSpanTreeValue = 0;
book = new bool[n];
toEdgeArr = new List <Edge <float> >();
for (int i = 0; i != n; i++)
{
toEdgeArr.Add(null);
}
for (int i = 0; i != n; i++)
{
book [i] = false;
}
indexMinHeap = new IndexMinHeap <float> (m);
book [0] = true;
visit(0);
while (indexMinHeap.Size() != 0)
{
int index = indexMinHeap.ExtraMinItemIndex();
Debug.Assert(toEdgeArr[index] != null);
book[index] = true;
visit(index);
// int u = toEdgeArr [index].U ();
// int v = toEdgeArr [index].V ();
// if (book [u] && !book [v]) {
// book [v] = true;
// visit (v);
// } else if(!book [u] && book [v]){
// book [u] = true;
// visit (u);
// }
}
for (int i = 1; i != n; i++)
{
minSpanTreeValue += toEdgeArr [i].weight;
}
}
//测试稠密有权图
//测试稀疏有权图
public void testWeightDSGraph()
{
string name = "";
string url = "";
//测试稠密有权图~
print("测试稠密有权图");
WeightDenseGraph <float> wdGraph = null;
name = "testWeightG1.txt";
url = FileHelper.FileNameHelper(name);
ReadWeightGraph.ReadGraphFromFile(url, out wdGraph, false); // out不可缺少
wdGraph.print();
//测试稀疏有权图
print("测试稀疏有权图");
WeightSpareGraph <float> wsGraph = null;
ReadWeightGraph.ReadGraphFromFile(url, out wsGraph, false);
wsGraph.print();
}
//使用深度优先搜索得到一棵深沉树
public LazyPrimMST(WeightSpareGraph <float> g, bool usingDSF)
{
this.g = g;
this.n = g.V();
oneSpantreeEdge = new List <Edge <float> > ();
oneSpanValue = 0f;
book = new bool[n];
for (int i = 0; i != n; i++)
{
book [i] = false;
}
for (int u = 0; u != n; u++)
{
if (!book [u])
{
book [u] = true;
DSF(u);
}
}
Debug.Log("一条生成树的长度为： " + oneSpanValue);
}
public BellmanFord(WeightSpareGraph <float> graph, int src)
{
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
this.src = src;
this.from = new int[n];
shortPathValue = new float[n];
for (int i = 0; i != n; i++)
{
from [i] = -1;
shortPathValue [i] = 9999f;
}
from [src] = -1;
shortPathValue [src] = 0f;
for (int i = 0; i != n - 1; i++)
{
for (int u = 0; u != n; u++)
{
WeightSpareGraph <float> .adjIterator iter =
new WeightSpareGraph <float> .adjIterator(graph, u);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
//
int v = e.Other(u);
if (shortPathValue [v] > shortPathValue [u] + e.weight)
{
from [v] = u;
shortPathValue [v] = shortPathValue [u] + e.weight;
}
}
}
}
isContainNegativeCircle = detectNegetiveCircle();
}
public adjIterator(WeightSpareGraph <Weight> graph, int v)
{
this.graph = graph;
this.v = v;
index = 0;
}
public KrusalMST(WeightSpareGraph <float> graph)
{
this.graph = graph;
this.n = graph.V();
this.m = graph.E();
book = new bool[n];
for (int i = 0; i != n; i++)
{
book [i] = false;
}
minSpanTreeValue = 0f;
minSpanTreeEdge = new List <Edge <float> > ();
//遍历图将所有的边加入allEdge数组
allEdge = new List <Edge <float> >();
for (int i = 0; i != n; i++)
{
WeightSpareGraph <float> .adjIterator iter =
new WeightSpareGraph <float> .adjIterator(graph, i);
for (Edge <float> e = iter.begin(); !iter.isEnd(); e = iter.Next())
{
int u = e.U();
int v = e.V();
if (u < v)
{
allEdge.Add(e);
}
}
}
Edge <float>[] edges = allEdge.ToArray();
QuickSorts(edges, edges.Length);
string str = "";
for (int i = 0; i != edges.Length; i++)
{
str += edges [i].ToString() + "\n";
}
Debug.Log(str);
// UnionFind unionFind = new UnionFind (edges.Length);
UnionFind uf = new UnionFind(n);
for (int i = 0; i != edges.Length; i++)
{
int u = edges [i].U();
int v = edges [i].V();
if (uf.isConnected(u, v))
{
continue;
}
uf.Union_Rank(u, v);
minSpanTreeEdge.Add(edges[i]);
}
for (int i = 0; i != minSpanTreeEdge.Count; i++)
{
minSpanTreeValue += minSpanTreeEdge [i].weight;
}
Debug.Log("n,m = " + n + ", " + m);
//犯了一个致命的错误， = =虽然数组只有两个状态连或者不连，但是
//当两个都是false的时候，下面设置为true，这样代表他与第一组也连了，但实际上是没有连的。
//修改~一旦两个都是false，与下一个交换= =还是不行。还是用并查集。
// minSpanTreeEdge.Add (edges[0]);
// book [edges [0].U ()] = true;
// book [edges [0].V ()] = true;
// for (int i = 1; i != edges.Length; i++) {
// int u = edges [i].U ();
// int v = edges [i].V ();
//
// if (book [u] == book [v]) {
// //both true
// if (book [u])
// continue;
// //both false
// AlgorithmsHelp.Swap(edges[i],edges[i+1]);
// book [u] = true;
// book [v] = true;
// minSpanTreeEdge.Add (edges [i]);
// } else {
// //either
// book[u] = true;
// book [v] = true;
// minSpanTreeEdge.Add (edges [i]);
// }
//
// }
//深度搜索建立并查集,错了。
// for (int i = 0; i != n; i++) {
// if (!book [i]) {
// book [i] = true;
// DSF (i);
//
// }
// }
}
