[leetcode] 91. Decode Ways

https://leetcode.com/problems/decode-ways/description/

Decode Ways - LeetCode

https://www.techiedelight.com/ko/count-decodings-sequence-of-digits/

주어진 숫자 시퀀스의 카운트 디코딩

class Solution:
    def numDecodings(self, s: str) -> int:
        if s == "": 
            return 0

        size = len(s)
        
        dp = [0 for x in range(size + 1)]
        dp[0] = 1

        for i in range(1, size + 1):
            if s[i - 1] != "0":
                dp[i] += dp[i - 1]

            if i != 1 and s[i - 2:i] < "27" and s[i - 2:i] > "09":
                dp[i] += dp[i - 2]

        return dp[len(s)]