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942. DI String Match

Difficulty Topics

Description

A permutation perm of n + 1 integers of all the integers in the range [0, n] can be represented as a string s of length n 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 permutation perm and return it. If there are multiple valid permutations perm, return any of them.

 

Example 1:

Input: s = "IDID"
Output: [0,4,1,3,2]

Example 2:

Input: s = "III"
Output: [0,1,2,3]

Example 3:

Input: s = "DDI"
Output: [3,2,0,1]

 

Constraints:

  • 1 <= s.length <= 105
  • s[i] is either 'I' or 'D'.

Solution

di-string-match.py
class Solution:
    def diStringMatch(self, s: str) -> List[int]:
        res = []
        n = len(s)
        queue = deque([x for x in range(n + 1)])

        for x in s:
            if x == "I":
                res.append(queue.popleft())
            else:
                res.append(queue.pop())

        res.append(queue.pop())

        return res