1 // Prim算法.cpp : 定义控制台应用程序的入口点。
2 //
3
4 #include "stdafx.h"
5 #include <stdio.h>
6 #include <string>
7 #include <queue>
8 #include <stdlib.h>
9 using namespace std;
10 #define Max 10
11 #define Infinity 1000
12 typedef unsigned int EdgeType;
13 typedef unsigned int DistType;
14 typedef int VexType;
15
16
17 struct Graph //图结构 包括边点数，边数组，访问标记，从初始点到点的路径长度。
18 {
19 int Arc;int Vex;
20 EdgeType Edge[Max][Max];
21 bool Vis[Max];
22 DistType Dist[Max];
23 };
24
25 struct QueElem //Que节点这个节点的设计主要是为了在使用优先级队列时比较方便
26 {
27 VexType V;
28 DistType D;
29 friend bool operator > (struct QueElem Q1,struct QueElem Q2)
30 {
31 return Q1.D> Q2.D;
32 }
33 };
34
35 typedef struct QueElem Q;
36
37 //priority_queue<Q,vector<Q>,greater<Q> > PriorQue;
38 priority_queue<Q,vector<Q>,greater<Q> > PriorQue; //申明优先级队列，建立小顶堆。
39 Q QueArr[Max]; //队列数组
40
41 void ReadGraph(Graph *G) //读图函数
42 {
43 int x,y;
44 int weigh;
45 printf("请输入点数和边数！\n");
46 scanf("%d%d",&(G->Vex),&(G->Arc));
47 memset(G->Edge,-1,sizeof(G->Edge));
48 memset(G->Vis,0,sizeof(G->Vis));
49 memset(G->Dist,-1,sizeof(G->Dist));
50 for(int i=0;i<G->Arc;i++)
51 {
52 printf("请输入第%d条边的起点终点和权值:",i+1);
53 scanf("%d%d%u",&x,&y,&weigh);
54 G->Edge[x][y]=weigh;
55 G->Edge[y][x]=weigh;
56 }
57 #if 0
58 for(int i=0;i<G->Vex;i++)
59 {
60 Vis[i]=false;
61 Dist[i]=Infinity;
62 }
63 #endif
64
65 G->Dist[0]=0;
66 for(int i=0;i<Max;i++)
67 {
68 QueArr[i].V=i;
69 QueArr[i].D=G->Dist[i];
70 }
71
72 }
73
74
75 void Prim(Graph *G)
76 {
77 int i;
78 Q pQ;
79 PriorQue.push(QueArr[0]);//推入头数组元素
80
81 while(!PriorQue.empty())
82 {
83 pQ=PriorQue.top(); //这个语句要用好，他和那个operator函数息息相关，注意operator参数只能为引用或者原型，不能指针
84 printf("pQ=%d\n",pQ.V);
85 PriorQue.pop();
86 G->Vis[pQ.V]=true;
87 for(i=0;i<G->Vex;i++)
88 {
89 if(G->Edge[pQ.V][i]< Infinity && !(G->Vis[i]) ) //检验是否有边和是否已访问
90 {
91 if(G->Dist[pQ.V]+G->Edge[pQ.V][i]<G->Dist[i])
92 {
93 G->Dist[i]=G->Dist[pQ.V]+G->Edge[pQ.V][i];
94 QueArr[i].D=G->Dist[i];
95 }
96 PriorQue.push(QueArr[i]);
97 }
98 }
99 }
100 }
101
102
103
104
105 int _tmain(int argc, _TCHAR* argv[])
106 {
107 Graph *G=(Graph *)malloc(sizeof (struct Graph));
108 ReadGraph(G);
109 Prime(G);
110 for(int i=0;i<G->Vex;i++)
111 printf("G->Dist[%d]=%u\n",i,G->Dist[i]);
112 return 0;
113 }
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