/in/foo.c: In function 'main':
/in/foo.c:6:7: warning: statement with no effect [-Wunused-value]
  k>=0 && k<n;
  ~~~~~^~~~~~
/in/foo.c:6:3: warning: 'k' is used uninitialized in this function [-Wuninitialized]
  k>=0 && k<n;
  ~^~~
/in/foo.c:6:11: warning: 'n' is used uninitialized in this function [-Wuninitialized]
  k>=0 && k<n;
          ~^~