foo.c:21:15: error: expected ';', ',' or ')' before '&' token
foo.c: In function 'bfs':
foo.c:36:1: warning: implicit declaration of function 'swap' [-Wimplicit-function-declaration]
foo.c:49:8: error: incompatible types when assigning to type 'struct <anonymous>' from type 'struct <anonymous> *'
foo.c: In function 'main':
foo.c:83:11: error: 'i' undeclared (first use in this function)
foo.c:83:11: note: each undeclared identifier is reported only once for each function it appears in
foo.c:80:6: warning: variable 'ppp' set but not used [-Wunused-but-set-variable]