1 // Kruskal算法.cpp : 定义控制台应用程序的入口点。
2 //
3
4 #include "stdafx.h"
5 #include <queue>
6 #include <string>
7 #include <iostream>
8 using namespace std;
9 #define Infinity 1000
10 #define Max 20
11 typedef int ElemType;
12 typedef unsigned int EdgeType;
13 typedef int DisjSet;
14 typedef int SetType;
15 struct Edge
16 {
17 ElemType From;
18 ElemType To;
19 EdgeType Weight;
20 friend bool operator> (Edge e1,Edge e2)
21 {
22 return e1.Weight>e2.Weight;
23 }
24 };
25
26
27 struct Graphic //图结构
28 {
29 int Arc;
30 int Vex;
31 Edge EdgeNode[Max];//边数组
32 // ElemType VexNode[Max];
33 DisjSet S[Max]; //不相交集合数组
34
35 };
36 typedef struct Graphic* Graph;
37
38 priority_queue<Edge,vector<Edge>,greater<Edge> > EQ; //优先级队列
39
40 void SetUnion(DisjSet S[],SetType Root1,SetType Root2) //不相交集合的合并
41 {
42 S[Root2]=Root1;
43 }
44
45 SetType Find(ElemType X,DisjSet S[]) //不相交集合的find算法 这里我们采用算法导论的不相交集合find层层上溯
46 {
47 if(S[X]!=X)
48 S[X]=Find(S[X],S);
49
50 return S[X];
51
52 }
53
54 void ReadGraph(Graph G) //读图函数
55 {
56 int i;
57 for( i=0;i<Max;i++)
58 G->EdgeNode[i].Weight=Infinity;
59 printf("请输入点数和边数: ");
60 scanf("%d%d",&(G->Vex),&(G->Arc));
61 for( i=0;i<Max;i++)
62 {
63 if(i<G->Vex)
64 G->S[i]=i;
65 else
66 G->S[i]=Infinity;
67 }
68 for( i=0;i<G->Arc;i++)
69 {
70 printf("请输入第%d条边的起点终点和权值:",i+1);
71 scanf("%d%d%u",&(G->EdgeNode[i].From),&(G->EdgeNode[i].To),&(G->EdgeNode[i].Weight));
72 EQ.push(G->EdgeNode[i]) ;
73 }
74
75 }
76
77
78 void Kruskal(Graph G)
79 {
80 ElemType U,V;
81 Edge e;
82 SetType Uset,Vset;
83 int EdgeAccepted=0;
84 while(EdgeAccepted<G->Vex-1)
85 {
86 e=EQ.top(); //弹出最小边
87 printf("e=%d\n",e.Weight);
88 EQ.pop();
89 U=e.From;
90 V=e.To;
91 Uset=Find(U,G->S); //查找最小边的起点
92 Vset=Find(V,G->S); //查找最小边的终点
93 if(Uset!=Vset) //不相交集合的合并
94 {
95 EdgeAccepted++;
96 SetUnion(G->S,Uset,Vset);
97 }
98 }
99 for(int i=0;i<G->Vex;i++)
100 printf("G->S[%d]=%d \n",i,G->S[i]);
101 }
102
103
104
105
106 int _tmain(int argc, _TCHAR* argv[])
107 {
108 Graph G=(Graph)malloc(sizeof(struct Graphic));
109 ReadGraph(G);
110 Kruskal(G);
111
112 return 0;
113 }
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