accessing vector elements in random order and update new values

A=[2 3 5]
B=[1 6 4]
X=[0 50 110 0 45]
Y=[250 0 0 35 0  120]

A and B are indices of X and Y respectively. I want to access in order (2,1)(3,6)(5,4) such that

1. if X(A)<Y(B) then X(A)-Y(B),(50-250) now X=[0 0 110 0 45] and Y=[200 0 0 35 0 120]
2. if X(A)>Y(B) then X(A)-Y(B),(110-120) now X=[0 0 0 0 45] and y=[200 0 0 35 0 10]
3. final answer is X=[0 0 0 0 10 ]| then Y=[200 0 0 10 0 10]

How can I do that? Thanks in advance.

for r=1:length(X)

if X(A)<Y(B)

          Ynew=minus(Y(B),X(A))

          Y(B)=Ynew

               X(A)=0

              Xnew=X(A)

              Anew=X+1

else  if X(A)>Y(B)

    for  r=1:length(b)

      Xnew=minus(X(A),Y(B))

         X(A)=Xnew

               Y(B)=0

              Ynew=Y(B)

               Ynew=Y+1

    end
  end    
  end 
  end

Answer 1

[KSSV]

A=[2 3 5] ;
B=[1 6 4] ;
X=[0 50 110 0 45] ;
Y=[250 0 0 35 0  120] ;
X0=X ;
Y0=Y ;

for i = 1:length(A)
    if X(A(i))<Y(B(i))
        Y(B(i))=Y(B(i))-X(A(i)) ;
        X(A(i))=0 ;
    elseif  X(A(i))>Y(B(i))
        Y(B(i))=Y(B(i))-X(A(i)) ;
        X(A(i))=0 ;
    end
end