cat <<'X'
 int M=N-1@
 E *A=malloc((long)M*sizeof(E))@
 E *B=malloc((long)M*sizeof(E))@
 for(m=1@m!=N@++m){
  double x=(double)d[m]/((int)nn[m]*(int)nn[m])@
  A[m-1].v=x@ A[m-1].id=m@
  B[m-1].v=x*x@ B[m-1].id=m@
 }
 qsort(A,M,sizeof(E),cmp)@
 qsort(B,M,sizeof(E),cmp)@
 double delta=1e-12, best=1e100@
 int ba=0, bb=0@
 while(best > delta){
  int j=0@
  int i@
  for(i=0@i!=M@++i){
   while(j!=M && (A[i].v-delta) > B[j].v) ++j@
   int k=j@
   while(k!=M && !(B[k].v > A[i].v+delta)){
    int ma=A[i].id, mb=B[k].id@
    if(ma!=mb && ((ma&mb)==mb)){
     double dd=A[i].v-B[k].v@
     if(dd > 0) {} else dd=-dd@
     if(best > dd){ best=dd@ ba=ma@ bb=mb@ }
    }
    ++k@
   }
  }
  printf("delta %.17g best %.17g b=%d a=%d\n",delta,best,__builtin_popcount(bb),__builtin_popcount(ba))@
  if(!(best > delta)) break@
  delta=delta*10.0@
 }
X