/in/foo.cc: In function 'int main()':
/in/foo.cc:15:18: warning: iteration 2 invokes undefined behavior [-Waggressive-loop-optimizations]
    if(a[i]==CAT[j])
             ~~~~~^
/in/foo.cc:13:16: note: within this loop
   for(int j=1;j<x+1;j++)
               ~^~~~