/in/foo.c: In function 'main':
/in/foo.c:9:15: warning: implicit declaration of function 'JinZhi21' [-Wimplicit-function-declaration]
   printf("%d",JinZhi21(a,x));
               ^~~~~~~~
/in/foo.c:11:15: warning: implicit declaration of function 'JinZhi22' [-Wimplicit-function-declaration]
   printf("%d",JinZhi22(a,x));
               ^~~~~~~~
/in/foo.c: In function 'JinZhi21':
/in/foo.c:26:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.c: In function 'JinZhi22':
/in/foo.c:52:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^