void SORTW(int *A, int *B, int *W)
{
 int I,J,K,M,N,TEMP,  D[NN];

  N=A[0];
 for (K=1; K<=N; K++) D[K]=A[K]*1000000 + B[K]*10000 + W[K];
 for (I=1; I<N; I++)
  {
   M=D[I]; K=I;
   for (J=I+1; J<=N; J++) if (D[J]<M) {M=D[J]; K=J;}
   if (K!=I) {TEMP=D[I]; D[I]=D[K]; D[K]=TEMP;}
  }
       /****** Removal of duplicates in D[ ] *******/

  J=1;
  for (K=2; K<=N; K++) if (D[K-1] != D[K]) {J++; D[J]=D[K];}
  N=J;  /* possibly different number of links */

       /******** place results back in A,B,W *********/

 for (K=1; K<=N; K++)
  {A[K]=D[K]/1000000; TEMP=D[K]%1000000; B[K]=TEMP/10000; W[K]=TEMP%10000;}
 A[0]=N;  A[N+1]=0; B[N+1]=0; W[N+1]=0;
 return;
}