aparler/RosettaCodeData
1
0
Fork 0
Code Issues 12 Pull requests 3 Projects Releases Packages Wiki Activity Actions

Another update from ingydotnet^djgoku

Browse source
This commit is contained in:
Ingy döt Net 2015-11-18 06:14:39 +00:00
parent 91df62d461
commit 948b86eafa
7604 changed files with 108452 additions and 22726 deletions
Download patch file Download diff file Expand all files Collapse all files

21
Task/N-queens-problem/Python/n-queens-problem-5.py
View file

@ -3,18 +3,21 @@ def queens(n):
up = [True]*(2*n - 1)
down = [True]*(2*n - 1)
def sub(i):
nonlocal a, up, down
for k in range(i, n):
j = a[k]
p = i + j
q = i - j + n - 1
if up[p] and down[q]:
if i == n - 1:
yield tuple(a)
else:
if i == n:
yield tuple(a)
else:
for k in range(i, n):
j = a[k]
p = i + j
q = i - j + n - 1
if up[p] and down[q]:
up[p] = down[q] = False
a[i], a[k] = a[k], a[i]
yield from sub(i + 1)
up[p] = down[q] = True
a[i], a[k] = a[k], a[i]
yield from sub(0)
#Count solutions for n=8:
sum(1 for p in queens(8))
92