992a9686ca
* wrap/python/Makefile.am (EXTRA_DIST): Add it. (python_PYTHON, MAINTAINERCLEANFILES): Add buddy.py. (pyexec_LTLIBRARIES): Add _buddy.la. (_buddy_la_SOURCES, _buddy_la_LDFLAGS, $(srcdir)/buddy_wrap.cxx) ($(srcdir)/buddy.py): New. * wrap/python/tests/bddnqueen.py: New file. * wrap/python/tests/Makefile.am (TESTS): Add it.
79 lines
1.7 KiB
Python
Executable file
79 lines
1.7 KiB
Python
Executable file
# Python translation of the C++ example from the BuDDy distribution.
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# (compare with buddy/examples/queen/queen.cxx)
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import ltihooks
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import sys
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from buddy import *
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# Build the requirements for all other fields than (i,j) assuming
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# that (i,j) has a queen.
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def build(i, j):
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a = b = c = d = bddtrue
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# No one in the same column.
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for l in side:
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if l != j:
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a &= X[i][j] >> -X[i][l]
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# No one in the same row.
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for k in side:
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if k != i:
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b &= X[i][j] >> -X[k][j]
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# No one in the same up-right diagonal.
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for k in side:
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ll = k - i + j
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if ll >= 0 and ll < N:
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if k != i:
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c &= X[i][j] >> -X[k][ll]
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# No one in the same down-right diagonal.
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for k in side:
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ll = i + j - k
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if ll >= 0 and ll < N:
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if k != i:
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c &= X[i][j] >> -X[k][ll]
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global queen
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queen &= a & b & c & d
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# Get the number of queens from the command-line, or default to 8.
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if len(sys.argv) > 1:
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N = int(argv[1])
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else:
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N = 8
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side = range(N)
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# Initialize with 100000 nodes, 10000 cache entries and NxN variables.
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bdd_init(N * N * 256, 10000)
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bdd_setvarnum(N * N)
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queen = bddtrue
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# Build variable array.
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X = [[bdd_ithvar(i*N+j) for j in side] for i in side]
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# Place a queen in each row.
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for i in side:
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e = bddfalse
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for j in side:
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e |= X[i][j]
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queen &= e
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# Build requirements for each variable(field).
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for i in side:
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for j in side:
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print "Adding position %d, %d" % (i, j)
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build(i, j)
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# Print the results.
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print "There are", bdd_satcount(queen), "solutions"
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print "one is:"
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solution = bdd_satone(queen)
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bdd_printset(solution)
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print
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bdd_done()
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