Floyd算法C语言实现

来源：互联网发布：js怎么定义多维数组编辑：程序博客网时间：2024/05/11 01:39
<pre name="code" class="objc">#include <stdio.h>#include <stdlib.h>#include <limits.h>#define NUM 4typedef struct MGraph/* 邻接表存储结构 */{     int edges[NUM][NUM];     int n,e;} MGraph;MGraph *build_mgraph();void Floyd(MGraph *mgraph);void Ppath(int path[][NUM], int i, int j);void Dispath(int A[][NUM], int path[][NUM], int n);int main(void){     MGraph *mgraph;     printf("\n*************************************************************\n");     printf("该图的矩阵表示为:\n");     mgraph=build_mgraph();     printf("\n*************************************************************\n");     printf("各顶点间最短路径为:\n");     Floyd(mgraph);     printf("\n*************************************************************\n");          return 0;}MGraph *build_mgraph(){     int i,j;     int num_e=0;     MGraph *mgraph=(MGraph *)malloc(sizeof(MGraph));     int matrix[NUM][NUM]={{0,5,INT_MAX,7},   {INT_MAX,0,4,2},   {3,3,0,2},   {INT_MAX,INT_MAX,1,0}};     for(i=0;i<NUM;i++)     {  for(j=0;j<NUM;j++)  {       mgraph->edges[i][j]=matrix[i][j];       if(matrix[i][j]!=0 && matrix[i][j]!=INT_MAX)    num_e++;  }     }     mgraph->n=NUM;     mgraph->e=num_e;     printf("node=%d;edges=%d\n",mgraph->n,mgraph->e);     for(i=0;i<NUM;i++)     {  for(j=0;j<NUM;j++)  {       if(mgraph->edges[i][j]!=INT_MAX)    printf("%3d",mgraph->edges[i][j]);       else    printf("%3c",'&');  }  printf("\n");     }     return mgraph;}void Floyd(MGraph *mgraph){     int A[NUM][NUM],path[NUM][NUM];     int i,j,k;     for(i=0;i<mgraph->n;i++)     {  for(j=0;j<mgraph->n;j++)  {       A[i][j]=mgraph->edges[i][j];       path[i][j]=-1;  }     }     for(k=0;k<mgraph->n;k++)     {  for(i=0;i<mgraph->n;i++)  {       for(j=0;j<mgraph->n;j++)       {    if(A[i][k]!=INT_MAX && A[k][j]!=INT_MAX && A[i][j]>A[i][k]+A[k][j])    { A[i][j]=A[i][k]+A[k][j]; path[i][j]=k;    }       }  }     }     Dispath(A,path,mgraph->n);}void Ppath(int path[][NUM], int i, int j){     int k;     k=path[i][j];     if(k==-1)  return;     Ppath(path,i,k);     printf("%d,",k);     Ppath(path,k,j);}void Dispath(int A[][NUM], int path[][NUM], int n){     int i,j;     for(i=0;i<n;i++)     {  for(j=0;j<n;j++)  {       if(A[i][j]==INT_MAX)    printf("%d-%d have no path",i,j);       printf("%d-%d-%d: ",i,j,A[i][j]);       printf("%d,",i);       Ppath(path,i,j);       printf("%d\n",j);  }     }}
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