/in/foo.cc: In function 'int InterSet(int*, int, int*, int, int*)':
/in/foo.cc:28:6: error: 'k' was not declared in this scope
   if(k!=-1 && k2==-1)
      ^
/in/foo.cc:26:7: warning: unused variable 'k1' [-Wunused-variable]
   int k1=Search(b,nb, a[i]);
       ^~