python求解水仙花数的方法

#!/usr/bin/python
def get_flower(n, ofile):
 D_pow=[pow(i,n) for i in range(0,10)]
 V_min=1*pow(10,n-1)
 V_max=sum((9*pow(10,x) for x in range(0,n)))
 T_count=0
 print D_pow, V_max, V_min
 nums=[1]+[0]*(n-1)
 print 'Start:', nums
 idx=n-1
 tmp_l=[0]*10
 while True:
  nums[idx]+=1
  if nums[idx]<10:
   j=idx+1
   while j<n:
    nums[j]=nums[idx] # reset 
    j+=1
   v=sum((D_pow[x] for x in nums))
   if v<=V_max and v>=V_min:
    T_count+=1
    #test if is flower
    #print 'do test:', ''.join(map(str,nums))
    k=0
    while k<10:
     tmp_l[k]=0
     k+=1
    N=0
    for k in nums:
     tmp_l[k]+=1
     N+=1
    while N>0:
     p=v%10
     if tmp_l[p]>0:
      tmp_l[p]-=1
      N-=1
     else:
      break
     v/=10
    if N==0:
     print >>ofile, 'hit', sum((D_pow[x] for x in nums))
   idx=n-1
  elif idx==0:
   print 'done'
   break
  else:
   idx-=1
 print 't_count', T_count
if __name__ == '__main__':
 with file('./f.txt', 'wb') as o:
  get_flower(21, o)
  #get_flower(3, o)