/in/foo.c: In function 'main':
/in/foo.c:3:17: error: expected ';', ',' or ')' before '&' token
 void my_swap(int&x,int&y);
                 ^
/in/foo.c:5:1: error: expected declaration specifiers before 'printf'
 printf("input three integer n1,n2,n3:");
 ^~~~~~
/in/foo.c:6:1: error: expected declaration specifiers before 'scanf_s'
 scanf_s("%d,%d,%d",%n1,&n2,&n3);
 ^~~~~~~
/in/foo.c:7:4: error: expected declaration specifiers before 'if'
    if(n1>n2)
    ^~
/in/foo.c:11:1: error: expected declaration specifiers before 'if'
 if(n1>n3)
 ^~
/in/foo.c:15:1: error: expected declaration specifiers before 'if'
 if (n2,n3)
 ^~
/in/foo.c:19:5: error: expected declaration specifiers before 'printf'
     printf("Now,the ascending order is:%d,%d,%d\n", n1, n2, n3);
     ^~~~~~
/in/foo.c:20:1: error: expected declaration specifiers before 'return'
 return 0;
 ^~~~~~
/in/foo.c:21:1: error: expected declaration specifiers before '}' token
 }
 ^
/in/foo.c:23:18: error: expected ';', ',' or ')' before '&' token
 void my_swap(int &x,int %y)
                  ^
/in/foo.c:4:11: error: declaration for parameter 'n3' but no such parameter
 int n1,n2,n3;
           ^~
/in/foo.c:4:8: error: declaration for parameter 'n2' but no such parameter
 int n1,n2,n3;
        ^~
/in/foo.c:4:5: error: declaration for parameter 'n1' but no such parameter
 int n1,n2,n3;
     ^~
/in/foo.c:32:1: error: expected '{' at end of input
 }
 ^