# include
# define Infinity 999999
# define size 40
int i,k,j;
void Input(int , int a[size][size]);
void Output(int , int a[size][size]);
void Flyod(int , int a[size][size], int r[size][size]);
void Input(int n, int a[size][size])
{
int i, j;
printf("\n Input adjacency matrix\n");
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
scanf("%d", &a[i][j]);
printf("\n");
}
}
void Output (int n, int a[size][size])
{
int i, j;
for (i =0; i < n; i++)
{
for (j =0; j < n; j++)
printf(" %d", a[i][j]);
printf("\n");
}
}
void Flyod(int n, int a[size][size], int r[size][size])
{
for (i = 0; i < n; i ++)
a[i][i] = 0; /* Set diagonal elements zero */
printf("\n After setting diagonal elements to zero \n");
Output(n, a);
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
{
if ((a[i][j] == 0) && (i != j))
r[i][j] = Infinity;
else
r[i][j] = a[i][j];
}
}
printf("\n Replacing zeros by very large value \n");
Output(n, r);
for (k = 0; k < n; k++)
{
for (i = 0; i < n; i++)
{
for (j = 0; j < n; j++)
{
if (r[i][k] + r[k][j]< r[i][j])
{
printf("\n r[%d][%d] = %d ", i, k, r[i][k]);
printf("\n r[%d][%d] = %d ", k, j, r[k][j]);
printf("\n r[%d][%d] = %d ", i, j, r[i][j]);
r[i][j] = r[i][k] + r[k][j];
printf("\n r[%d][%d] = r[%d][%d] + r[%d][%d] = %d ", i, j, i, k, k, j, r[i][j]);
}
else
{
r[i][j] = r[i][j];
printf("\n r[%d][%d] = r[%d][%d] = %d ", i, j, i, j, r[i][j]);
}
}
printf("\n");
}
printf("\n Step %d \n", k);
Output (n,r);
}
}
main()
{
int a[size][size];
int r[size][size];
int n;
printf("\n Input number of vertices in the graph: ");
scanf("%d", &n);
Input(n,a);
printf("\n Adjacency matrix\n");
Output(n,a);
Flyod(n,a,r);
printf("\n Shortest path matrix \n");
Output(n,r);
}
