/in/foo.cc: In function 'int main()':
/in/foo.cc:13:10: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   {if(i=0)
          ^
/in/foo.cc:15:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
    else if(i=1)
               ^
/in/foo.cc:17:15: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
    else if(i=2)
               ^
/in/foo.cc:22:21: warning: format '%d' expects argument of type 'int', but argument 2 has type 'int*' [-Wformat=]
  printf("%d\n",&tail);}
                     ^