/in/foo.c:1:1: error: stray '\347' in program
 然后递归 ，下面算法按思路2解 
 ^
/in/foo.c:1:2: error: stray '\204' in program
 然后递归 ，下面算法按思路2解 
  ^
/in/foo.c:1:3: error: stray '\266' in program
 然后递归 ，下面算法按思路2解 
   ^
/in/foo.c:1:4: error: stray '\345' in program
 然后递归 ，下面算法按思路2解 
    ^
/in/foo.c:1:5: error: stray '\220' in program
 然后递归 ，下面算法按思路2解 
     ^
/in/foo.c:1:6: error: stray '\216' in program
 然后递归 ，下面算法按思路2解 
      ^
/in/foo.c:1:7: error: stray '\351' in program
 然后递归 ，下面算法按思路2解 
       ^
/in/foo.c:1:8: error: stray '\200' in program
 然后递归 ，下面算法按思路2解 
        ^
/in/foo.c:1:9: error: stray '\222' in program
 然后递归 ，下面算法按思路2解 
         ^
/in/foo.c:1:10: error: stray '\345' in program
 然后递归 ，下面算法按思路2解 
          ^
/in/foo.c:1:11: error: stray '\275' in program
 然后递归 ，下面算法按思路2解 
           ^
/in/foo.c:1:12: error: stray '\222' in program
 然后递归 ，下面算法按思路2解 
            ^
/in/foo.c:1:14: error: stray '\357' in program
 然后递归 ，下面算法按思路2解 
              ^
/in/foo.c:1:15: error: stray '\274' in program
 然后递归 ，下面算法按思路2解 
               ^
/in/foo.c:1:16: error: stray '\214' in program
 然后递归 ，下面算法按思路2解 
                ^
/in/foo.c:1:17: error: stray '\344' in program
 然后递归 ，下面算法按思路2解 
                 ^
/in/foo.c:1:18: error: stray '\270' in program
 然后递归 ，下面算法按思路2解 
                  ^
/in/foo.c:1:19: error: stray '\213' in program
 然后递归 ，下面算法按思路2解 
                   ^
/in/foo.c:1:20: error: stray '\351' in program
 然后递归 ，下面算法按思路2解 
                    ^
/in/foo.c:1:21: error: stray '\235' in program
 然后递归 ，下面算法按思路2解 
                     ^
/in/foo.c:1:22: error: stray '\242' in program
 然后递归 ，下面算法按思路2解 
                      ^
/in/foo.c:1:23: error: stray '\347' in program
 然后递归 ，下面算法按思路2解 
                       ^
/in/foo.c:1:24: error: stray '\256' in program
 然后递归 ，下面算法按思路2解 
                        ^
/in/foo.c:1:25: error: stray '\227' in program
 然后递归 ，下面算法按思路2解 
                         ^
/in/foo.c:1:26: error: stray '\346' in program
 然后递归 ，下面算法按思路2解 
                          ^
/in/foo.c:1:27: error: stray '\263' in program
 然后递归 ，下面算法按思路2解 
                           ^
/in/foo.c:1:28: error: stray '\225' in program
 然后递归 ，下面算法按思路2解 
                            ^
/in/foo.c:1:29: error: stray '\346' in program
 然后递归 ，下面算法按思路2解 
                             ^
/in/foo.c:1:30: error: stray '\214' in program
 然后递归 ，下面算法按思路2解 
                              ^
/in/foo.c:1:31: error: stray '\211' in program
 然后递归 ，下面算法按思路2解 
                               ^
/in/foo.c:1:32: error: stray '\346' in program
 然后递归 ，下面算法按思路2解 
                                ^
/in/foo.c:1:33: error: stray '\200' in program
 然后递归 ，下面算法按思路2解 
                                 ^
/in/foo.c:1:34: error: stray '\235' in program
 然后递归 ，下面算法按思路2解 
                                  ^
/in/foo.c:1:35: error: stray '\350' in program
 然后递归 ，下面算法按思路2解 
                                   ^
/in/foo.c:1:36: error: stray '\267' in program
 然后递归 ，下面算法按思路2解 
                                    ^
/in/foo.c:1:37: error: stray '\257' in program
 然后递归 ，下面算法按思路2解 
                                     ^
/in/foo.c:1:38: error: expected identifier or '(' before numeric constant
 然后递归 ，下面算法按思路2解 
                                      ^
/in/foo.c:1:39: error: stray '\350' in program
 然后递归 ，下面算法按思路2解 
                                       ^
/in/foo.c:1:40: error: stray '\247' in program
 然后递归 ，下面算法按思路2解 
                                        ^
/in/foo.c:1:41: error: stray '\243' in program
 然后递归 ，下面算法按思路2解 
                                         ^
In file included from /usr/include/stdio.h:74:0,
                 from /in/foo.c:4:
/usr/include/libio.h:302:3: error: unknown type name 'size_t'
   size_t __pad5;
   ^~~~~~
/usr/include/libio.h:305:67: error: 'size_t' undeclared here (not in a function)
   char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)];
                                                                   ^~~~~~
/usr/include/libio.h:333:62: error: expected declaration specifiers or '...' before 'size_t'
 typedef __ssize_t __io_read_fn (void *__cookie, char *__buf, size_t __nbytes);
                                                              ^~~~~~
/usr/include/libio.h:342:6: error: expected declaration specifiers or '...' before 'size_t'
      size_t __n);
      ^~~~~~
/usr/include/libio.h:464:19: error: expected '=', ',', ';', 'asm' or '__attribute__' before '_IO_sgetn'
 extern _IO_size_t _IO_sgetn (_IO_FILE *, void *, _IO_size_t);
                   ^~~~~~~~~
In file included from /in/foo.c:4:0:
/usr/include/stdio.h:339:20: error: expected declaration specifiers or '...' before 'size_t'
       int __modes, size_t __n) __THROW;
                    ^~~~~~
/usr/include/stdio.h:388:44: error: expected declaration specifiers or '...' before 'size_t'
 extern int snprintf (char *__restrict __s, size_t __maxlen,
                                            ^~~~~~
/usr/include/stdio.h:392:45: error: expected declaration specifiers or '...' before 'size_t'
 extern int vsnprintf (char *__restrict __s, size_t __maxlen,
                                             ^~~~~~
/usr/include/stdio.h:711:15: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'fread'
 extern size_t fread (void *__restrict __ptr, size_t __size,
               ^~~~~
/usr/include/stdio.h:717:15: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'fwrite'
 extern size_t fwrite (const void *__restrict __ptr, size_t __size,
               ^~~~~~