题解 | #外观数列#

#
# 
# @param n int整型 
# @return string字符串
#
class Solution:
    def countAndSay(self , n):
        # write code here
        arr = ['1']
        for i in range(1,n):
            sum = 1
            s = ''
            temp = arr[i-1]
            for j in range(1,len(temp)):
                if temp[j] == temp[j-1]:
                    sum +=1
                else:
                    s += str(sum) + temp[j-1]
                    sum = 1
            s += str(sum) + temp[len(temp)-1]
            arr.append(s)
        return arr[n-1]