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#!/usr/bin/python
# -*- coding: utf-8 -*-
def solveIt(n):
# Modify this code to run your puzzle solving algorithm
# define the domains of all the variables (0..n-1)
domains = [range(0,n)]*n
# start a trivial depth first search for a solution
sol = tryall([],domains)
# prepare the solution in the specified output format
# if no solution is found, put 0s
outputData = str(n) + '\n'
if sol == None:
print 'no solution found.'
outputData += ' '.join(map(str, [0]*n))+'\n'
else:
outputData += ' '.join(map(str, sol))+'\n'
return outputData
# this is a depth first search of all assignments
def tryall(assignment, domains):
# base-case: if the domains list is empty, all values are assigned
# check if it is a solution, return None if it is not
if len(domains) == 0:
if checkIt(assignment):
return assignment
else:
return None
# recursive-case: try each value in the next domain
# if we find a solution return it. otherwise, try the next value
else:
for v in domains[0]:
sol = tryall(assignment[:]+[v],domains[1:])
if sol != None:
return sol
# checks if an assignment is feasible
def checkIt(sol):
n = len(sol)
for i in range(0,n):
for j in range(i+1,n):
if sol[i] == sol[j] or \
sol[i] == sol[j] + (j-i) or \
sol[i] == sol[j] - (j-i):
return False
return True
import sys
if __name__ == "__main__":
if len(sys.argv) > 1:
try:
n = int(sys.argv[1].strip())
except:
print sys.argv[1].strip(), 'is not an integer'
print 'Solving Size:', n
print(solveIt(n))
else:
print('This test requires an instance size. Please select the size of problem to solve. (i.e. python queensSolver.py 8)')
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