/in/foo.c: In function 'main':
/in/foo.c:11:19: warning: statement with no effect [-Wunused-value]
  for(int i=0;i++;i<n)
                  ~^~
/in/foo.c:12:11: warning: unknown conversion type character ' ' in format [-Wformat=]
   scanf("% ",a[i]);
           ^
/in/foo.c:12:9: warning: too many arguments for format [-Wformat-extra-args]
   scanf("% ",a[i]);
         ^~~~
/in/foo.c:14:2: error: expected expression before 'int'
  int max=a[0];
  ^~~
/in/foo.c:15:11: error: 'max' undeclared (first use in this function); did you mean 'main'?
   if(a[i]>max)
           ^~~
           main
/in/foo.c:15:11: note: each undeclared identifier is reported only once for each function it appears in
/in/foo.c:10:15: warning: unused variable 'b' [-Wunused-variable]
  int a[10000],b[10];
               ^
/in/foo.c: In function 'ming':
/in/foo.c:26:9: error: expected expression before ')' token
  switch()
         ^
/in/foo.c:33:2: error: 'i' undeclared (first use in this function)
  i++;
  ^
/in/foo.c:34:10: error: 'max' undeclared (first use in this function); did you mean 'main'?
  if(a[i]=max)
          ^~~
          main
/in/foo.c:35:3: error: break statement not within loop or switch
   break;
   ^~~~~
/in/foo.c: In function 'lu':
/in/foo.c:41:2: error: 'i' undeclared (first use in this function)
  i++;
  ^
/in/foo.c:42:9: error: expected expression before ')' token
  switch()
         ^
/in/foo.c:49:10: error: 'max' undeclared (first use in this function); did you mean 'main'?
  if(a[i]=max)
          ^~~
          main
/in/foo.c:50:3: error: break statement not within loop or switch
   break;
   ^~~~~
/in/foo.c: In function 'ming':
/in/foo.c:38:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.c: In function 'lu':
/in/foo.c:53:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^