Introduction to Soft Computing: Neuro-Fuzzy and Genetic Algorithms

486 Introduction to Soft Computing

and there are two positions in row 2, viz., at column 3, and 4, at which Q

1

and Q

2

are not attacking

each other.  erefore, we choose column 3 for

Q

2

.  e resulting partial solution is shown as node 2

of Fig. 11.87. However, this assignment leaves no valid position for the third queen, Q

3

.  erefore,

the process backtracks to the latest backtracking point which is at node (1).  e other position for

queen Q

2

is now tried with. It is seen that this allows a valid position for Q

3

but leaves nowhere to

place queen Q

4

.  erefore, the algorithm has to backtrack. Since all alternatives out of placing queen ...