Dr. Gail Lange's feedback - Floyd

[dusteenie]

The code was excellent, except for printing out paths where there was more than one
intermediate vertex as in the case:
v0 v4 v1 v
v4 v1 v2 v3

Your code has:
public static void path(int q, int r)
{
if (P[q, r] != -1)
{
Console.Write("\nPath [" + q + ", " + r + "]\t");
path(q, P[q, r]);
Console.Write("v" + P[q, r] + " ");
path(P[q, r], r);
}

    }

whereas the code should be:

public static void path(int q, int r, int[][] P)
{
if (P[q][r] != -1)
{
path(q, P[q][r], P);
Console.Write(" v" + P[q][r] + " ");
path(P[q][r], r, P);
}
}

Adding even a line of code in a recursive function can cause different outputs from what expected.

Below is my code:
for (i = 0; i < numVertex; i++) // Output all shortest paths
for (j = 0; j < numVertex; j++)
{
if (P[i][j] != -1)
/* there is a path with intermediate vertices. Does not print if there is
just an edge between v[i] and v[j] */
{
Console.WriteLine("The shortest path between vertex " + i +
" and vertex " + j + " is:");
Console.Write("v" + i);
path(i, j, P);
Console.Write("v" + j);
Console.WriteLine();
}

                if (i != j && P[i][j] == -1 && D[i][j] != INFINITY)
                {
                    Console.WriteLine("The shortest path between vertex " + i +
                        " and vertex " + j + " is:");
                    Console.WriteLine("v" + i + "   v" + j);
                }
            }