Lab 06
import time
import random
import math
class Board(object):
"""An N-queens solution attempt."""
def __init__(self, queens):
"""Instances differ by their queen placements."""
self.queens = queens.copy()
def display(self):
"""Print the board."""
for r in range(len(self.queens)):
for c in range(len(self.queens)):
if self.queens[c] == r:
print('Q', end=" "),
else:
print('-', end=" "),
print('\n')
print('\n')
def moves(self):
"""Return a list of possible moves given the current placements."""
moves=[]
for i in self.queens:
tup=[]
if self.queens[i]+1 in range(0,8):
tup.append(self.queens(i)+1,i)
if self.queens[i]-1 in range(0,8):
tup.append(self.queens[i]-1,i)
moves.append(tup)
return moves
def LineCountQueen(self,r):
nr = 0
for i in range(len(self.queens)):
if self.queens[i] == r:
nr+=1
return nr
def DiagCountQueen(self,c):
nr = 0
for i in range(len(self.queens)):
Row = abs(self.queens[c]-self.queens[i])
Col = abs(c-i)
if(Col==Row):
nr+=1
if nr>0:
return int(nr-1)
return 0
def neighbor(self,move):
self.queens[0]=move[0]
def cost(self):
nr = 0
for i in range(len(self.queens)):
nr+=self.LineCountQueen(self.queens[i])
for i in range(len(self.queens)):
nr+=self.DiagCountQueen(i)
return nr
class Agent(object):
"""Knows how to solve an n-queens problem with simulated annealing."""
def anneal(self, board):
"""Return a list of moves to adjust queen placements."""
# YOU FILL THIS IN
def main():
"""Create a problem, solve it with simulated anealing, and console-animate."""
print("Enter the number of queens")
n = 8
queens = dict()
for column in range(n):
row = random.choice(range(n))
queens[column] = row
board = Board(queens)
board.display()
agent = Agent()
path = agent.anneal(board)
while path:
move = path.pop(0)
board = board.neighbor(move)
time.sleep(0.1)
board.display()
if __name__ == '__main__':
main()