Ifi6057w5ex

N lipu paigutamine lokaalse otsinguga.

 import search
 import random

 class HCNQueens(search.Problem):
   def __init__(self, N):
       self.N = N
       self.initial = [None]*N
       for i in range(N):
           self.initial[i] = random.randint(0,N-1)

   def actions(self, state):
       acts = []
       for i in range(self.N):
           pos = state[i]
           for j in range(self.N):
               if j == pos: continue
               acts.append((i, j))
       return acts

   def result(self, state, action):
       i, j = action
       newstate = list(state)
       newstate[i] = j
       return newstate

   def conflict(self, row1, col1, row2, col2):
       """Would putting two queens in (row1, col1) and (row2, col2) conflict?"""
       return (row1 == row2 or  # same row
               col1 == col2 or  # same column
               row1 - col1 == row2 - col2 or  # same \ diagonal
               row1 + col1 == row2 + col2)   # same / diagonal

   def value(self, state):
       h = 0
       for col in range(self.N - 1):
           row = state[col]
           for col2 in range(col + 1, self.N):
               row2 = state[col2]
               if self.conflict(row, col, row2, col2):
                   h += 1
       return h

 def hill_climbing(problem):
   current = problem.initial
   curr_value = problem.value(problem.initial)

   while True:
       max_value = 99999
       for action in problem.actions(current):
           neighbor = problem.result(current, action)
           neigh_value = problem.value(neighbor)
           if neigh_value < max_value:
               max_neighbor = neighbor
               max_value = neigh_value

       if max_value >= curr_value:
           break
       else:
           current = max_neighbor
           curr_value = max_value
           print (curr_value, current)

   return current

 p = HCNQueens(36)
 print(p.value(p.initial), p.initial)
 #print(p.value([2,1,2,1]))
 #print (p.actions(p.initial))
 #print (p.result(p.initial,p.actions(p.initial)[0]))

 print(hill_climbing(p))