/in/foo.cc: In function 'int main()':
/in/foo.cc:7:13: warning: iteration 4 invokes undefined behavior [-Waggressive-loop-optimizations]
   a[i]=a[i+1];
        ~~~~~^
/in/foo.cc:6:15: note: within this loop
  for(int i=0;i<5;i++){
              ~^~
/in/foo.cc:5:5: warning: array subscript is above array bounds [-Warray-bounds]
  a[6]=a[0];
  ~~~^