foo.c: In function 'main':
foo.c:59:22: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
              xunhuan = xunhuan->next;
                      ^
foo.c:65:33: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
                         xunhuan = xunhuan->next;
                                 ^
foo.c:78:31: warning: assignment from incompatible pointer type [-Wincompatible-pointer-types]
                 xunhuan->next = ttmp;
                               ^

自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。