Supporting Continuous Skyline Queries in Dynamically Weighted Road Networks

Algorithm 3

Update the skyline set.

input interested points set A, dominant relationship M₁, comparison of distance M_2.

output skyline set SKY

Steps:

A.SortByDistance(); // sort points in A by distance attribute

for(i=1;i<=A.MaxNum;i++) // updateM2

for(j=1;j<=i;j++)

if(M2[i][j].CompareFlag!=compare(A[i],A[j])) // if the relationship changes, update the relationship

M2[i][j].CompareFlag=compare(A[i],A[j]);

M2[i][j].Changed=true;

else

M2[i][j].Changed=false;

SKY.include(A); // initialize SKY

for(i=2;i<=A.MaxNum;i++) // compute SKY

foreach p in SKY

if(M2[i][p.id]. Changed) // if the relationship of distance attribute changes

M1[A[i].id][ p.id]=ComputeDominate(A[i],p); // compute dominant relationship and update M1

if(!SKY. Dominate(A[i],M1)) // judge whether there is a point in SKY that dominates A[i] according to M1

SKY.include(A[i]); // if no point dominates A[i], add A[i] to SKY

return SKY;