Introduction

Problem Jay likes sequences, so he use to playing with a sequence of size N. He will transform the sequence according to K queries, and the format and process of the queries are as follows: L R X: Let’s say the sequence sorted in ascending order is A[1], A[2], …, A[N].

Problem The H-Index is a metric that measures the productivity and impact of a scientist’s research. It represents the highest number h such that the scientist has published h papers that have each been cited at least h times. According to Wikipedia, the H-Index is calculated as follows: For a given scientist who has published n papers, if h of these papers have at least h citations each, and the other papers have no more than h citations each, then h is the maximum value for this scientist’s H-Index.

Problem Given an array of non-negative integers, your task is to determine the largest number that can be formed by concatenating the integers together. For example, with the integers [6, 10, 2], you can form the numbers [6102, 6210, 1062, 1026, 2610, 2106] through different arrangements. The largest number from these combinations is 6210.

Problem To find a number at the k-th position after slicing and sorting the array from the i-th to j-th number, consider the following: For example, if the array is [1, 5, 2, 6, 3, 7, 4], i = 2, j = 5, and k = 3, slicing the array from the 2nd to the 5th number yields [5, 2, 6, 3].

Problem A “tuple” is defined as an ordered collection of elements which can include duplicate values and each element is assigned an order. A tuple with n elements (a1, a2, a3, ..., an) can be expressed using the set notation in various ways, with any ordering of the subsets as:

Problem Define a string as a “valid bracket string” if it follows the given rules: “()”, “[]”, and “{}” are all valid bracket strings. If A is a valid bracket string, then “(A)”, “[A]”, and “{A}” are also valid bracket strings. For example, since “[]” is a valid bracket string, “([])” is also valid.