A Prefiltered Cuckoo Search Algorithm with Geometric Operators for Solving Sudoku Problems

Algorithm 7

AC3/GAC3.

Input: 𝑋,𝐷,𝐶

Output: Boolean

(1)  𝑄←(𝑥_𝑖,𝑐)∣𝑐∈𝐶,𝑥_𝑖∈𝑋(𝑐)

(2)  While 𝑄≠∅ do

(3)   select and remove (𝑥_𝑖,𝑐) from 𝑄

(4)   If Revise3(𝑥_𝑖,𝑐) then

(5)    If 𝐷(𝑥_𝑖)=∅ then

(6)     Return false

(7)    Else

(8)     𝑄←𝑄∪{(𝑥_𝑗,𝑐^′)∣𝑐^′∈𝐶∧𝑐^′≠𝑐∧𝑥_𝑖,𝑥_𝑗∈𝑋(𝑐^′)∧𝑗≠𝑖}

(9)    End If

(10)   End If

(11)  End While

(12)  Return true