kruskal(c++).txt

计算机算法程序

*
  Name:最小生成树kruskal算法 
*/

＃i nclude<stdio.h>
＃i nclude<stdlib.h>
#define M 20
#define MAX 20

typedef struct 
{
 int begin;
 int end;
 int weight;
}edge;

typedef struct
{
 int adj;
 int weight;
}AdjMatrix[MAX][MAX];

typedef struct
{
 AdjMatrix arc;
 int vexnum, arcnum;
}MGraph;
void CreatGraph(MGraph *);//函数申明 
void sort(edge* ,MGraph *);
void MiniSpanTree(MGraph *);
int  Find(int *, int );
void Swapn(edge *, int, int);
void CreatGraph(MGraph *G)//构件图
{
 int i, j,n, m;

 printf("请输入边数和顶点数:");
 scanf("%d %d",&G->arcnum,&G->vexnum);
 
    for (i = 1; i <= G->vexnum; i++)//初始化图
 {
  for ( j = 1; j <= G->vexnum; j++)
  {
   G->arc[i][j].adj = G->arc[j][i].adj = 0;
  }
 }

 for ( i = 1; i <= G->arcnum; i++)//输入边和权值 
 {
  printf("\n请输入有边的2个顶点");
  scanf("%d %d",&n,&m);
  while(n < 0 || n > G->vexnum || m < 0 || n > G->vexnum)
  {
   printf("输入的数字不符合要求 请重新输入:");
   scanf("%d%d",&n,&m);
  }
     
  G->arc[n][m].adj = G->arc[m][n].adj = 1;
  getchar();
  printf("\n请输入%d与%d之间的权值:", n, m);
  scanf("%d",&G->arc[n][m].weight);
 }
    
 printf("邻接矩阵为:\n");
 for ( i = 1; i <= G->vexnum; i++)
 { 
  for ( j = 1; j <= G->vexnum; j++)
  {
      printf("%d ",G->arc[i][j].adj);
  }
     printf("\n");
 }
}

void sort(edge edges[],MGraph *G)//对权值进行排序 
{
 int i, j;

 for ( i = 1; i < G->arcnum; i++)
 {
  for ( j = i + 1; j <= G->arcnum; j++)
  {
   if (edges[i].weight > edges[j].weight)
   {
    Swapn(edges, i, j);
   }
  }
 }
    
 printf("权排序之后的为:\n");
 for (i = 1; i < G->arcnum; i++)
 {
     printf("<< %d, %d >>   %d\n", edges[i].begin, edges[i].end, edges[i].weight);
 }

}

void Swapn(edge *edges,int i, int j)//交换权值 以及头和尾 
{  
 
 int temp;   
  
 temp = edges[i].begin;  
    edges[i].begin = edges[j].begin;
    edges[j].begin = temp;
    temp = edges[i].end;  
    edges[i].end = edges[j].end;
    edges[j].end = temp;
    temp = edges[i].weight;  
    edges[i].weight = edges[j].weight;
    edges[j].weight = temp;
} 

void MiniSpanTree(MGraph *G)//生成最小生成树 
{
 int i, j, n, m;
 int k = 1;
    int parent[M];

 edge edges[M];
 
 for ( i = 1; i < G->vexnum; i++)
 {
  for (j = i + 1; j <= G->vexnum; j++)
  {
   if (G->arc[i][j].adj == 1)
   {
    edges[k].begin = i;
    edges[k].end = j;
    edges[k].weight = G->arc[i][j].weight;
       k++;
   }
   
  }
 }
        
    sort(edges, G);
    for (i = 1; i <= G->arcnum; i++)
 {
  parent[i] = 0;
 }
    printf("最小生成树为:\n");
 for (i = 1; i <= G->arcnum; i++)//核心部分 
 {
  n = Find(parent, edges[i].begin);
  m = Find(parent, edges[i].end);
  if (n != m)
  {
     parent[n] = m;
     printf("<< %d, %d >>   %d\n", edges[i].begin, edges[i].end, edges[i].weight);
  }
 }
}

int Find(int *parent, int f)//找尾 
{
 while ( parent[f] > 0)
 {
  f = parent[f];
 }
    return f;
}

int main(void)//主函数 
{
 MGraph *G;

 G = (MGraph*)malloc(sizeof(MGraph));
 if (G == NULL)
 {
  printf("memory allcation failed,goodbye");
  exit(1);
 }
    
 CreatGraph(G);
    MiniSpanTree(G);
   
 system("pause");
 return 0;
}