Backtrack---N Queen

pos=[0]*5
x=[0]*5

def place(t):
 for i in range(1,t):
  if (pos[i] == pos[t]):
   return False
  elif (abs(pos[i]-pos[t]) == abs(i-t)):
   return False
 return True

def Backtrack(t,n):
 if (t>n):
  print "get an answer"
  print pos
 else:
  for i in range(1, n+1):
   pos[t]=i
   if (place(t)):
    Backtrack(t+1, n)

def Queen(n):
  Backtrack(1,n)

Queen(4)

Backtrack---N Queen

原文：http://www.cnblogs.com/zhaodonglin/p/5445018.html