/in/foo.cc: In function 'int main()':
/in/foo.cc:92:11: warning: 'sy' may be used uninitialized in this function [-Wmaybe-uninitialized]
     printf("%.3f", mem_dfs(sum, sx, sy, h));
     ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:92:11: warning: 'sx' may be used uninitialized in this function [-Wmaybe-uninitialized]