(11C) Mahjong scores

[Rogier]

The cross-exchange is complicated. That' s why my first efforts didn't fit. It's just too cumbersome. The example is the way it's done by hand, the old fashioned way with chips of bone representing money.

The fastest way we came up with is:

• Each player receives 4 times the number of points he/she scored, unless EAST won, in which case they each receive 3 times the number of points scored.
• Each player pays the total number of points scored by all players, except for the winner, who doesn’t pay at all, and EAST, who pays double
  

Maybe your idea comes down to the same.

Now, presume in my example EAST wins:
EAST: 28 points (at least 20 more; bonus for winning. Let's keep it at that)
SOUTH: 20 points
WEST: 144 points (8*22 points less, because no bonuses for winning and winning tile)
NORTH: 64 points

Result:
> SOUTH, NORTH and WEST each pay 2x28= 56 points to EAST
> NORTH pays 144-64 = 80 points to WEST
> SOUTH pays 64-20 = 44 points to NORTH
> SOUTH pays 144-20 = 124 points to WEST
All in all:
> EAST gains 3x2x28 = 168 points
> SOUTH loses 56 + 44 +124 = 224 points
> WEST gains (124 + 80) - 56= 148 points
> NORTH loses 44 - (56 + 80) = 92 points
check: 168 + 148 - 224 - 92 = 0