848. 字母移位

[JalanJiang]

• 原题链接：848. 字母移位
• 题解链接：http://jalan.space/leetcode-notebook/#/data-structure/string/?id=_848-%e5%ad%97%e6%af%8d%e7%a7%bb%e4%bd%8d

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• 输出题解
• 时间复杂度
• 是否最优解

[JalanJiang]

class Solution:
    def shiftingLetters(self, S: str, shifts: List[int]) -> str:
        length = len(shifts)
        num = [0 for _ in range(length)]
        num[length - 1] = shifts[length - 1]
        for i in range(length - 2, -1, -1):
            num[i] = shifts[i] + num[i + 1]
        
        s_list = list(S)
        ord_a = ord('a')
        ord_z = ord('z')
        for i in range(length):
            shift = num[i] % 26
            c = s_list[i]
            ord_res = ord(c) + shift
            if ord_res > ord_z:
                ord_res = ord_res - ord_z - 1 + ord_a
            s_list[i] = chr(ord_res)
        
        return "".join(s_list)

[csming1995]

Java解法:

class Solution {
    public String shiftingLetters(String S, int[] shifts) {
        char[] chars = S.toCharArray();

        for (int i = 0; i < S.length(); i++) {
            for (int j = 0; j < i; j++) {
                shifts[j] = (shifts[i] + shifts[j]) % 26;
            }
        }

        for (int i = 0; i < S.length(); i++) {
            int index = chars[i] - 'a';
            int finalIndex = (index + shifts[i]) % 26;
            chars[i] = (char) ('a' + finalIndex);
        }

        return new String(chars);
    }
}