Given a string s consisting only of characters a, b and c. Return the number of substrings containing at least one occurrence of all these characters a, b and c.   Example 1: Input: s = "abcabc" Output: 10 Explanation: The substrings containing at least one…

给你一个长度为 m 的字符串 s，其中仅包含数字。另给你一个二维整数数组 queries，其中 queries[i] = [li, ri]。

You are given a string s of length m consisting of digits. You are also given a 2D integer array queries, where queries[i] = [li, ri]. For each queries[i], extract the substring s[li..ri]. Then, perform the following:

返回 s 字典序最小的子序列，该子序列包含 s 的所有不同字符，且只包含一次。   示例 1： 输入：s = "bcabc" 输出："abc" 示例 2： 输入：s = "cbacdcbc" 输出："acdb"   提示：

Given a string s, return the lexicographically smallest subsequence of s that contains all the distinct characters of s exactly once.   Example 1: Input: s = "bcabc" Output: "abc" Example 2: Input: s = "cbacdcbc" Output: "acdb"   Constraints:

给你一个长度为 n 的二进制字符串 s，其中：

You are given a binary string s of length n, where:

给你一个长度为 n 的二进制字符串 s ，其中：

You are given a binary string s of length n, where:

给你一个 回文 字符串 s。 返回 s 的按字典序排列的 最小 回文排列。 如果一个字符串从前往后和从后往前读都相同，那么这个字符串是一个 回文 字符串。 排列 是字符串中所有字符的重排。

You are given a palindromic string s. Return the lexicographically smallest palindromic permutation of s.   Example 1: Input: s = "z" Output: "z" Explanation: A string of only one character is already the lexicographically smallest palindrome. Example 2:…

给你一个 回文 字符串 s 和一个整数 k。

You are given a palindromic string s and an integer k. Return the k-th lexicographically smallest palindromic permutation of s. If there are fewer than k distinct palindromic permutations, return an empty string. Note: Different rearrangements that yield…