/*Prepare the distance matrix in file ff.dat
  s is the membership array for the solution set, empty initially
  f is that for the frontier set, frontier = {1} initially */
#include <stdio.h>
main(){
int i,j,k,n,v,w,source;
int d[1000],f[1000],s[1000];
int a[100][100];
FILE *in_file;
  printf("Input n and source ");
  in_file=fopen("ff.dat","r"); 
  fscanf(in_file,"%d",&n);
  for (i=1;i<=n;i++) {
    for (j=1;j<=n;j++) fscanf(in_file, "%d ",&a[i][j]);
    fscanf(in_file, "\n");
  };
  for (i=1;i<=n;i++){
    for (j=1;j<=n;j++) printf("%4d ",a[i][j]);
    printf("\n");
  }
  for (k=1;k<=n;k++) {
    for (i=1;i<=n;i++)
      for (j=1;j<=n;j++)
        if (a[i][k]+a[k][j]<a[i][j]){
           a[i][j]=a[i][k]+a[k][j];
           printf("( %d , %d )", i, j);
        }
    printf("\n");
  for (i=1;i<=n;i++){
    for (j=1;j<=n;j++) printf("%4d ",a[i][j]);
    printf("\n");
  }
    getchar();;
  }
  printf("\n");
  for (i=1;i<=n;i++){
    for (j=1;j<=n;j++) printf("%4d ",a[i][j]);
    printf("\n");
  }
}