foo.c: In function 'dfs':
foo.c:36:3: warning: implicit declaration of function 'exit' [-Wimplicit-function-declaration]
   exit(0);
   ^~~~
foo.c:36:3: warning: incompatible implicit declaration of built-in function 'exit'
foo.c:36:3: note: include '<stdlib.h>' or provide a declaration of 'exit'
foo.c: In function 'main':
foo.c:56:10: warning: format '%s' expects argument of type 'char *', but argument 2 has type 'char (*)[1000]' [-Wformat=]
  scanf("%s%s%s",&s[0],&s[1],&s[2]);
          ^
foo.c:56:12: warning: format '%s' expects argument of type 'char *', but argument 3 has type 'char (*)[1000]' [-Wformat=]
  scanf("%s%s%s",&s[0],&s[1],&s[2]);
            ^
foo.c:56:14: warning: format '%s' expects argument of type 'char *', but argument 4 has type 'char (*)[1000]' [-Wformat=]
  scanf("%s%s%s",&s[0],&s[1],&s[2]);
              ^

自豪的采用jd5进行评测(github.com/masnn/jd5)