View Compilation Error

0_0_3095439_24776.c:11: error: syntax error before '&' token
0_0_3095439_24776.c: In function `dfs':
0_0_3095439_24776.c:13: error: `root' undeclared (first use in this function)
0_0_3095439_24776.c:13: error: (Each undeclared identifier is reported only once
0_0_3095439_24776.c:13: error: for each function it appears in.)
0_0_3095439_24776.c:16: error: `index' undeclared (first use in this function)
0_0_3095439_24776.c: At top level:
0_0_3095439_24776.c:31: error: syntax error before '&' token
0_0_3095439_24776.c: In function `creatbitree':
0_0_3095439_24776.c:34: error: `root' undeclared (first use in this function)
0_0_3095439_24776.c: At top level:
0_0_3095439_24776.c:59: error: syntax error before '&' token
0_0_3095439_24776.c: In function `post':
0_0_3095439_24776.c:61: error: `root' undeclared (first use in this function)
0_0_3095439_24776.c:63: error: `x' undeclared (first use in this function)