answer:def minRemovals(S): This function returns the minimum number of characters to be removed from the input string S to make each character appear an even number of times. from collections import Counter # Count occurrences of each character char_count = Counter(S) # Find characters that appear an odd number of times odd_count_chars = sum(1 for count in char_count.values() if count % 2 != 0) # To make an odd count to even, we need to remove 1 character return odd_count_chars

answer:def merge_meetings(meetings): Merge overlapping meeting times. :param meetings: A list of tuples where each tuple contains the start and end time of a meeting in 'HH:MM' format. :return: A list of tuples with consolidated meeting times. # Helper function to convert time in 'HH:MM' format to minutes def to_minutes(time): hours, minutes = map(int, time.split(':')) return hours * 60 + minutes # Helper function to convert minutes back to 'HH:MM' format def to_time(minutes): hours = minutes // 60 minutes = minutes % 60 return f"{hours:02d}:{minutes:02d}" # Convert meeting times to minutes for easier comparison and sorting meetings_in_minutes = [(to_minutes(start), to_minutes(end)) for start, end in meetings] # Sort meetings by start time (and by end time if start times are the same) meetings_in_minutes.sort() merged_meetings = [] for start, end in meetings_in_minutes: if not merged_meetings or merged_meetings[-1][1] < start: merged_meetings.append((start, end)) else: merged_meetings[-1] = (merged_meetings[-1][0], max(merged_meetings[-1][1], end)) # Convert merged meeting times back to 'HH:MM' format return [(to_time(start), to_time(end)) for start, end in merged_meetings]

answer:class FileSystem: def __init__(self): self.files = {} self.timestamp = 0 def _increment_timestamp(self): self.timestamp += 1 def _update_modtime(self, filename): self._increment_timestamp() self.files[filename]["modtime"] = self.timestamp def create(self, filename): if filename not in self.files: self.files[filename] = {"content": "", "modtime": None} self._update_modtime(filename) def write(self, filename, data): if filename in self.files: self.files[filename]["content"] = data self._update_modtime(filename) def read(self, filename): if filename in self.files: return self.files[filename]["content"] return "File not found" def delete(self, filename): if filename in self.files: del self.files[filename] def modtime(self, filename): if filename in self.files: return self.files[filename]["modtime"] return "File not found" def execute_operations(n, operations): fs = FileSystem() output = [] for operation in operations: parts = operation.split() if parts[0] == "CREATE": fs.create(parts[1]) elif parts[0] == "WRITE": filename = parts[1] data = " ".join(parts[2:]) fs.write(filename, data) elif parts[0] == "READ": result = fs.read(parts[1]) output.append(result) elif parts[0] == "DELETE": fs.delete(parts[1]) elif parts[0] == "MODTIME": result = fs.modtime(parts[1]) output.append(result) return output

answer:def count_unique_substrings_of_length_n(s, n): Returns the number of unique substrings of length exactly n in the input string s. if n > len(s): return 0 substrings = set() for i in range(len(s) - n + 1): substrings.add(s[i:i+n]) return len(substrings)