prepare (1/3): 
finished

make (2/3): 
clang -std=gnu11 -O2 -Wall  -o main main.c mst.c
main.c:21:35: warning: incompatible pointer types passing 'int (Edge *, Edge *)' (aka 'int (struct edge *, struct edge *)') to parameter of type '__compar_fn_t' (aka 'int (*)(const void *, const void *)') [-Wincompatible-pointer-types]
    qsort(graph, e, sizeof(Edge), edge_comp);
                                  ^~~~~~~~~
/usr/include/stdlib.h:828:20: note: passing argument to parameter '__compar' here
                   __compar_fn_t __compar) __nonnull ((1, 4));
                                 ^
main.c:27:35: warning: incompatible pointer types passing 'int (Edge *, Edge *)' (aka 'int (struct edge *, struct edge *)') to parameter of type '__compar_fn_t' (aka 'int (*)(const void *, const void *)') [-Wincompatible-pointer-types]
    qsort(res, num, sizeof(Edge), res_comp);
                                  ^~~~~~~~
/usr/include/stdlib.h:828:20: note: passing argument to parameter '__compar' here
                   __compar_fn_t __compar) __nonnull ((1, 4));
                                 ^
2 warnings generated.
main successfully constructed
finished

clean (3/3): 
finished

all task finished, build successfully