How to count the constraint check in aima csp

[ThuriyaThwin]

Here's an interesting line from the table Fig. 5.5, p. 143 of AIMA

              Backtrack    BT+MRV    Forward Checking  FC+MRV  Min-Conflicts

N-Queens (>40,000K) 13,500K (>40,000K) 817K 4K`

Here, N-Queens means the row is about the super-problem of solving ALL N-Queens problems for N from 2 to 50. The columns represent five different aproaches and the numbers are the computational cost of each. The differences are dramatic, and motivate this project. Numbers in parentheses mean 'no answer found after this much work'. More precisely, the numbers show the median number of basic consistency check operations (over five runs) for '2 to 50 queens' problems.

I wonder want to know how to count the constraint check in aima csp.
Please !

[iByteABit256]

In backtracking_search I did
res, checks = inference(...)
total_checks += checks
instead of just checking if inference is true
Also did some changes in forward_checking so it returns the checks as well.

I don't know if there's an easier way to do this

[dmeoli]

The CSP class now counts constraint checks. Background: csp.nassigns only counted variable assignments, and the AC-3/AC-3b/AC-4 routines returned a local checks count, but the backtracking/forward-checking path had no constraint-check tally — so the Figure 6.1 benchmark (BT / BT+MRV / FC / FC+MRV consistency checks) couldn't be reproduced.

Fixed in 996652b: the constraint relation is now exposed through a CSP.constraints() method that increments self.nchecks on every call (the raw relation is kept as self.constraint_relation). Since nconflicts, count_lost_values, forward_checking and the AC routines all go through it, csp.nchecks gives the total number of consistency checks. Example:

csp = MapColoringCSP(list('RGB'), 'SA: WA NT Q NSW V; NT: WA Q; NSW: Q V; T: ')
backtracking_search(csp)
print(csp.nassigns, csp.nchecks)   # assignments made, consistency checks performed

Closing as implemented.