foo.cc: In function 'int un(int*, int, int*)':
foo.cc:15:13: warning: unused variable 'i' [-Wunused-variable]
   15 |         int i=0,k=0;
      |             ^
foo.cc: In function 'int main()':
foo.cc:36:15: warning: 'memset' used with constant zero length parameter; this could be due to transposed parameters [-Wmemset-transposed-args]
   36 |         memset(h,sizeof(b),0);
      |         ~~~~~~^~~~~~~~~~~~~~~