난이도: MediumProblem Description 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.  Problem ExampleExample 1:Input: s = "abcabc"Output: 10Explanation: The substrings containing at least one occurrence of the characters a, b and c are "abc", "abca", "abcab", "abcabc", "bca", "bcab", "bcab..

난이도: MediumProblem DescriptionThere is a circle of red and blue tiles. You are given an array of integers colors and an integer k. The color of tile i is represented by colors[i]:colors[i] == 0 means that tile i is red.colors[i] == 1 means that tile i is blue.An alternating group is every k contiguous tiles in the circle with alternating colors (each tile in the group except the first and last o..

난이도: EasyProblem DescriptionYou are given a 0-indexed string blocks of length n, where blocks[i] is either 'W' or 'B', representing the color of the ith block. The characters 'W' and 'B' denote the colors white and black, respectively. You are also given an integer k, which is the desired number of consecutive black blocks. In one operation, you can recolor a white block such that it becomes a b..