# https://leetcode.com/problems/move-pieces-to-obtain-a-string

class Solution:
    def canChange(self, start: str, target: str) -> bool:
        length = len(start)
        start_char_list = []
        target_char_list = []
        for i in range(length):
            if start[i] != '_':
                start_char_list.append([start[i], i])
            if target[i] != '_':
                target_char_list.append([target[i], i])

        if len(start_char_list) != len(target_char_list):
            return False

        while len(start_char_list) > 0:
            start_char, start_index = start_char_list.pop()
            target_char, target_index = target_char_list.pop()
            not_okay = start_char != target_char or \
                (start_char == 'L' and start_index < target_index) or \
                (start_char == 'R' and start_index > target_index)
            if not_okay:
                return False

        return True