README.md

942. DI String Match

Given a string S that only contains "I" (increase) or "D" (decrease), let N = S.length.

Return any permutation A of [0, 1, ..., N] such that for all i = 0, ..., N-1:

• If S[i] == "I", then A[i] < A[i+1]
• If S[i] == "D", then A[i] > A[i+1]

Example 1:

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

Example 2:

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

Example 3:

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

Note:

1. 1 <= S.length <= 10000
2. S only contains characters "I" or "D".

Solutions (Python)

1. Solution

class Solution:
    def diStringMatch(self, S: str) -> List[int]:
        b, e = 0, len(S)
        A = []
        for di in S:
            if di == 'I':
                A.append(b)
                b += 1
            elif di == 'D':
                A.append(e)
                e -= 1
        A.append(b)
        return A