class Solution(object):
def permutation(self, narray, k, p):
if len(narray)<=1:
return narray
ind=k/p
rem=k%p
p/=len(narray)-1
ret=[narray[ind]]
del narray[ind]
ret.extend(self.permutation(narray, rem, p))
return ret
def getPermutation(self, n, k):
"""
:type n: int
:type k: int
:rtype: str
"""
p=1
for v in xrange(1,n):
p*=v
narray=[i+1 for i in xrange(n)]
return "".join(["%d"%v for v in self.permutation(narray, k-1, p)])