flloyd.c

#include<stdio.h>
int min(int,int);
void floyds(int p[1000][1000],int n)
{
 int i,j,k;
 for(k=1;k<=n;k++)
  for(i=1;i<=n;i++)
   for(j=1;j<=n;j++)
    if(i==j)
     p[i][j]=0;
    else
     p[i][j]=min(p[i][j],p[i][k]+p[k][j]);
}
int min(int a,int b)
{
 if(a<b)
  return(a);
 else
  return(b);
}
void main()
{
 int p[1000][1000],w,n,e,u,v,i,j,src,tar;
 printf("\n Enter the number of vertices:");
 scanf("%d",&n);
 printf("\n Enter the number of edges:\n");
 scanf("%d",&e);
 for(i=1;i<=n;i++)
 {
  for(j=1;j<=n;j++)
   p[i][j]=1000;
 }
 for(i=1;i<=e;i++)
 {
  //printf("\n Enter the end vertices of edge%d with its weight \n",i);
  scanf("%d %d %d",&u,&v,&w);
  p[u][v]=1;
 }
 /*printf("\n Matrix of input data:\n");
 for(i=1;i<=n;i++)
 {
  for(j=1;j<=n;j++)
   printf("%d \t",p[i][j]);
  printf("\n");
 }*/
 floyds(p,n);
 /*printf("\n Transitive closure:\n");
 for(i=1;i<=n;i++)
 {
  for(j=1;j<=n;j++)
   printf("%d \t",p[i][j]);
  printf("\n");
 }
 printf("\n The shortest paths are:\n");
 for(i=1;i<=n;i++)
  for(j=1;j<=n;j++)
  {
   if(i!=j)
    printf("\n <%d,%d>=%d",i,j,p[i][j]);
  }*/
  scanf("%d %d",&src,&tar);
  printf("%d\n",p[src][tar]);
}