Portability problem with pa02

graph02.c

128c128
<    for (int i=0; edges[i] != nilEdge; i++) {
---
>    for (int i=0; edges[i] != 0; i++) {
138c138
<       edge_ref *edges = malloc (maxN * sizeof (struct edge));
---
>       edge_ref *edges = calloc (maxN, sizeof (struct edge));