foo.c:2:1: error: unknown type name 'using'
    2 | using namespace std;
      | ^~~~~
foo.c:2:17: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'std'
    2 | using namespace std;
      |                 ^~~
foo.c: In function 'main':
foo.c:7:15: error: 'true' undeclared (first use in this function)
    7 |         while(true){
      |               ^~~~
foo.c:2:1: note: 'true' is defined in header '<stdbool.h>'; did you forget to '#include <stdbool.h>'?
    1 | #include <stdio.h>
  +++ |+#include <stdbool.h>
    2 | using namespace std;
foo.c:7:15: note: each undeclared identifier is reported only once for each function it appears in
    7 |         while(true){
      |               ^~~~
foo.c:8:17: error: 'y' undeclared (first use in this function)
    8 |                 y=x/2;
      |                 ^
foo.c:9:17: error: 'z' undeclared (first use in this function)
    9 |                 z=x%2
      |                 ^
foo.c:9:22: error: expected ';' before 'if'
    9 |                 z=x%2
      |                      ^
      |                      ;
   10 |                 if(y！=1)
      |                 ~~    
foo.c:14:17: error: 'else' without a previous 'if'
   14 |                 else
      |                 ^~~~
foo.c:15:32: warning: passing argument 1 of 'printf' makes pointer from integer without a cast [-Wint-conversion]
   15 |                         printf(1);
      |                                ^
      |                                |
      |                                int
In file included from foo.c:1:
/nix/store/3w4yrspgcx1z9wi18rv0hbap4jjlhx4c-glibc-2.37-8-dev/include/stdio.h:356:43: note: expected 'const char * restrict' but argument is of type 'int'
  356 | extern int printf (const char *__restrict __format, ...);
      |                    ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~
foo.c:5:15: warning: unused variable 'y\U0000ff0cz' [-Wunused-variable]
    5 |         int x,y，z;
      |               ^~~~

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