/in/foo.cc: In function 'int count(int, int)':
/in/foo.cc:19:13: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return ans-i;
             ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:19:13: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return ans-i;
             ^
/in/foo.cc:12:14: note: 'ans' was declared here
  int l=i,r=n,ans,mid;
              ^~~
/in/foo.cc:38:9: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   printf("%d\n",ans);
   ~~~~~~^~~~~~~~~~~~