prepare (1/3): 
finished

make (2/3): 
clang -std=gnu11 -O2 -Wall  -o main main.c UnionFind.c
main.c:91:39: warning: incompatible pointer types passing 'int (const Edge *, const Edge *)' to parameter of type '__compar_fn_t' (aka 'int (*)(const void *, const void *)') [-Wincompatible-pointer-types]
    qsort(graph, eSize, sizeof(Edge), Edge_cmp);
                                      ^~~~~~~~
/usr/include/stdlib.h:828:20: note: passing argument to parameter '__compar' here
                   __compar_fn_t __compar) __nonnull ((1, 4));
                                 ^
main.c:94:35: warning: incompatible pointer types passing 'int (const Edge *, const Edge *)' to parameter of type '__compar_fn_t' (aka 'int (*)(const void *, const void *)') [-Wincompatible-pointer-types]
    qsort(rev, num, sizeof(Edge), cmp2);
                                  ^~~~
/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