How to find minimum distance gateway node from a cluster head?

Hello every body.

I have a sensor network of 100 sensor nodes. sink.x=50; sink.y=120;

for i = 1 : 1 :n
    S(i).xd = rand(1,1)*xm ;
    S(i).yd = rand (1,1)*ym ;
    xd(i) = S(i).xd ;
    yd(i) = S(i).yd ;
    S(i).id = i;
    S(i).type = 0;
    S(i).g = 0 ;
    S(i).E = Eo ;
    S(i).type = 0 ;
    %     plot(S(i).xd, S(i).yd , 'o' )
    %     grid on ;
    %     hold on ;
    %     figure(1);
end

Next I have a set of 16 gateway nodes. Placed as follows

for i=1:1:16
    Sg(i).xd= 2+100*rand(1,1);
     Sg(i).yd=100;
    xd(i)=Sg(i).xd;
    yd(i)=Sg(i).yd;
    Sg(i).id=i;
    plot(Sg(i).xd,Sg(i).yd,'*k')
    grid on;
    hold on;
end

I have to form cluster heads from these sensor nodes using LEACH protocol. After the creation of cluster heads, I have to connect a gateway node with every cluster head. Condition gateway node should be at minimum distance from cluster head.

Please reply.

I know LEACH code. But no able to connect gateway node with min distance CH.

Thanks