/in/foo.c: In function 'main':
/in/foo.c:4:17: error: expected ';', ',' or ')' before '&' token
 void my_swap(int&x,int&y);
                 ^
/in/foo.c:7:1: warning: implicit declaration of function 'scanf_s' [-Wimplicit-function-declaration]
 scanf_s("%d,%d,%d",%n1,&n2,&n3);
 ^~~~~~~
/in/foo.c:7:20: error: expected expression before '%' token
 scanf_s("%d,%d,%d",%n1,&n2,&n3);
                    ^
/in/foo.c:10:2: warning: implicit declaration of function 'my_swap' [-Wimplicit-function-declaration]
  my_swap(n1,n2);
  ^~~~~~~
/in/foo.c:16:7: warning: left-hand operand of comma expression has no effect [-Wunused-value]
 if (n2,n3)
       ^
/in/foo.c: At top level:
/in/foo.c:24:18: error: expected ';', ',' or ')' before '&' token
 void my_swap(int &x,int %y)
                  ^