Eroare de compilare: user.c: In function ‘read’: user.c:39:26: error: ‘M’ undeclared (first use in this function) scanf("%d %d", &N, &M); ^ user.c:39:26: note: each undeclared identifier is reported only once for each function it appears in user.c: In function ‘solve’: user.c:56:19: error: ‘num_nodes’ undeclared (first use in this function) FOR(node, 1, num_nodes) { ^ user.c:5:31: note: in definition of macro ‘FOR’ #define FOR(a,b,c) for(a=b;a<=c;a++) ^ user.c: In function ‘read’: user.c:37:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(filename, "r", stdin); ^ user.c:43:15: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &i, &j); ^ user.c: In function ‘write’: user.c:87:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen(filename, "w", stdout); ^