This shouldn’t work ?!?
We’ve made the problem bigger, so how can it help?
Before, there were 93 107 possibilities
- now there are 25 = 32 times as many!
The constraints now involve fewer variables
- constraint propagation can happen sooner
- variables can be set sooner (reduced to one value)
- domain wipe out & backtracking occurs earlier
In ILOG Solver, this encoding needs only 212
- down from 8,018
- if that doesn’t impress you, call it minutes (or hours)