(60%) Develop a program to solve the Eight-Queen problem
mentioned in Exercise 6.26 (page 255) of Chapter 6.
To make it simple, we do not need to use any heuristics.
The basic strategy is to randomly pick a queen position that
will not be attacked by previously placed queens, and keep
doing this until all 8 queens are placed. If you cannot place
all 8 queens, print out the number of queens been placed and
start all over again.
A sample output list is as follows:
Try 1: 7 queens have been placed
Try 2: 6 queens have been placed
Try 3: 5 queens have been placed
Try 4: 7 queens have been placed
Try 5: 7 queens have been placed
Try 6: 7 queens have been placed
Try 7: 7 queens have been placed
Try 8: 5 queens have been placed
Try 9: Congratulations on successfully placed all 8 queens!
1 1 1 1 1 1 1 2
1 1 2 1 1 1 1 1
2 1 1 1 1 1 1 1
1 1 1 1 1 2 1 1
1 2 1 1 1 1 1 1
1 1 1 1 2 1 1 1
1 1 1 1 1 1 2 1
1 1 1 2 1 1 1 1
In the preceding output list, "2" denotes the location of the
queens.
Note that the total number of trys (9 in the above case)
should be something
between 1 and 100. If you program constantly takes more than
100 trys to solve the problem, then very probably there is a
bug in your program.