# https://leetcode.com/problems/shifting-letters-ii

from typing import List

class Solution:
    def convert(self, s: str, shift: int) -> str:
        return chr(
            (
                (ord(s) - ord('a') + shift) % 26
            ) + ord('a')
        )

    def shiftingLetters(self, s: str, shifts: List[List[int]]) -> str:
        l = len(s)
        shifting = [0] * (l + 1)
        for [start, end, direction] in shifts:
            if direction == 0:
                shifting[start] -= 1
                shifting[end + 1] += 1
            else:
                shifting[start] += 1
                shifting[end + 1] -= 1
        shift = 0
        result = []
        for i in range(len(s)):
            shift += shifting[i]
            result.append(self.convert(s[i], shift))
        return ''.join(result)