题目
By now, you are given a secret signature consisting of character ‘D’ and ‘I’. ‘D’ represents a decreasing relationship between two numbers, ‘I’ represents an increasing relationship between two numbers. And our secret signature was constructed by a special integer array, which contains uniquely all the different number from 1 to n (n is the length of the secret signature plus 1). For example, the secret signature “DI” can be constructed by array [2,1,3] or [3,1,2], but won’t be constructed by array [3,2,4] or [2,1,3,4], which are both illegal constructing special string that can’t represent the “DI” secret signature.
On the other hand, now your job is to find the lexicographically smallest permutation of [1, 2, … n] could refer to the given secret signature in the input.
解题思路
贪心，首先创建一个1到n的排列，对于连续的D，将对应的区间进行翻转
代码
class Solution:
def findPermutation(self, s: str) -> List[int]:
res = list(range(1, len(s) + 2))
for m in re.finditer('D+', s):
i, j = m.start(), m.end() + 1
res[i: j] = res[i: j][::-1]
return res
