[Pio-temporary] Ideas for AI playing development cards

[Roland C. <rc...@us...>]

Hello all,

There was a bug in the AI that prompted me to look a little closer at 
the AI code.

I think the AI could make better decisions when to play a development 
card. The AI is called greedy, so it should get as much resources and 
build as fast as it can, but I think it could delay some actions when 
it will have no direct benefit.

Year of Plenty:
Current: will be played anytime the bank has at least 2 resources. If 
the bank does not contain anything the AI likes, it will request the 
resources for a road, and if the bank is too empty, it will just pick 
something at random.

Proposed: the bank must have at least 2 resources. If the bank does 
not contain anyting the AI likes, determine whether it is possible to 
get enough resources to perform a maritime trade to get the resource 
the AI needs (in the next turn). If not, determine whether the AI is 
allowed to place a road [*1] and the resources are in the bank, and 
request that. If all fails: don't play this card yet.

Monopoly:
Current: will be played when the other players have at least six 
resources cards in total. If the AI doesn't need anything in 
particular, it will pick the resource that all players have the most 
of.

Proposed:  will be played when the other players have at least six 
resources cards in total. If the AI doesn't need anything in 
particular, don't play it yet.

Road building:
Current: play whenever two or more road segments are left.

Proposed: play whenever two or more road segments are left, but not 
when road segments are not allowed to be built [*1]

Gold:
Current: when the AI does want something, get it. Otherwise, start 
emptying the bank starting from the first resource.

Proposed: when the AI does want something, get it. Otherwise, start 
emptying the bank starting from the resource that has the best 
maritime trade ratio.

Regards,
Roland Clobus

[*1] Sometimes the AI is not allowed to build a road. Otherwise it 
would just build roads, and skip building settlements (which require 
also brick and wood)