0484. Find Permutation

https://leetcode.com/problems/find-permutation

Description

A permutation perm of n integers of all the integers in the range [1, n] can be represented as a string s of length n - 1 where:

• s[i] == 'I' if perm[i] < perm[i + 1], and

• s[i] == 'D' if perm[i] > perm[i + 1].

Given a string s, reconstruct the lexicographically smallest permutation perm and return it.

Example 1:

**Input:** s = "I"
**Output:** [1,2]
**Explanation:** [1,2] is the only legal permutation that can represented by s, where the number 1 and 2 construct an increasing relationship.

Example 2:

**Input:** s = "DI"
**Output:** [2,1,3]
**Explanation:** Both [2,1,3] and [3,1,2] can be represented as "DI", but since we want to find the smallest lexicographical permutation, you should return [2,1,3]

Constraints:

• 1 <= s.length <= 105

• s[i] is either 'I' or 'D'.

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