TYPES OF PERMUTATION PROBLEMS

locus or position problems (location in the gene is important)
     substitution cipher solver (e.g. key)
example:
abcdefghijklmnopqrstuvwxyz
govandlsbce...            key

adjacency problems (neighbors are important)
example:
TSP

** Cycle Xover - perserves cycles exchanges blocks
PMX - tends to do well.   modified 2point xover

	     p1: 1 2 3 4 5 6 7 8 9
	     p2: 9 3 7 8 2 6 5 1 4
             ch: 9 3 _ 4 5 6 7 1 _
replaced 8 and 2 with 7 and 4.
             ch: 9 3 2 4 5 6 7 1 8


	     p2: 9 3 7 8 2 6 5 1 4
             ch: 9 3 2 4 5 6 7 1 8
                 a b c d c e c f d             


** Order Xover (adjacency)
	     p1: 1 2 3 4 5 6 7 8 9
	     p2: 9 3 7 8 2 6 5 1 4
                      ^       ^
             ch: _ _ _ 4 5 6 7 _ _  copied from P1
                                    fill from P2

Not used from P2?
        9 3 8 2 1
              3 8 2 4 5 6 7 1 9  copied from P1


** Edge Xover (adjacency problems)
	     p1: 1 2 3 4 5 6 7 8 9
	     p2: 9 3 7 8 2 6 5 1 4

node adjNodes
1    2,9,5,4 
2    3,1,8,6 
3    4,2,9,7 
4    5,3,1,9 
5    6,4,1,6 
6    7,5,2,5 
7    8,6,3,8 
8    9,7,2,7 
9    1,8,4,3 

1 2,9,5,4  
2 3,1,8,6
3 4,2,9,7
4 5,3,1,9
5 6+,4,1
6 7,5+,2
7 8+,6,3
8 9,7+,2
9 1,8,4,3

order of picking
1. pick a edge in both parents
2. entry in shortest list (greedy)
3. if list not empty pick at random from the list
4. if list is empty grow in opposite direction
5. pick any random node to keep going