n = int(input.strip)s = input.striptotal_substrings = n * (n + 1) // 2ans = total_substringsfor i in range(n - 1): if s[i] != s[i + 1]: left_choices = i + 1 right_choices = n - i - 1 ans += left_choices * right_choicesprint(ans)摘要:n = int(input.strip)s = input.striptotal_substrings = n * (n + 1) // 2ans = total_substringsfor i in range(n - 1): if s[i] != s[i
来源:易道