python-leetcode面试题解之第38题外观数列-python题解.zip

class Solution: def countAndSay(self, n): """ :type n: int :rtype: str """ if n == 1: return '1' x = '1' while n > 1: # each round, read itself x = self.count(x) n -= 1 return x def count(self, x): m = list(x) res = [] m.append(None) i , j = 0 , 0 while i < len(m) - 1: j += 1 if m[j] != m[i]: # note j - i is the count of m[i] res += [j - i, m[i]] i = j return ''.join(str(s) for s in res)