This article introduces how to solve LeetCode problem 960: Sort an array of strings by removing columns. The goal of this problem is to find the minimum number of columns to remove so that the remaini

Abstract: This problem describes the initial state of 8 prison cells. The current cell state is updated daily based on the states of adjacent cells (the first and last cells are always 0). Given the n

Abstract: The problem asks whether a given even-length array can be reordered such that each odd-numbered element is twice the number of its preceding element. The solution is to count the frequency o

The problem involves maximizing a score by strategically playing tokens either face-up (spending power to gain score) or face-down (spending score to gain power). The solution involves sorting the tok

Summary: The problem involves determining the number of columns to delete from a grid of strings to ensure all remaining columns are sorted lexicographically. The solution iterates through each column

Summary: The problem checks if an array is a valid mountain array, which must: Have length ≥ 3 Strictly increase to a peak (not at the ends) Strictly decrease after the peak End at the last element Ap

Abstract: Given a set of points on a plane, calculate the minimum area of ​​a rectangle formed by these points with sides parallel to the coordinate axes. If no such rectangle exists, return 0. Soluti

This problem involves reordering log files based on specific criteria. The solution separates logs into letter-logs (containing letters after the identifier) and digit-logs (containing digits). Letter

The problem involves tracking recent requests within a 3000-millisecond window. The solution uses a RecentCounter class with a dynamically expanding array to store request timestamps. The key optimiza

This problem requires counting the number of distinct email addresses that actually received the emails. The processing rules include:The period ('.') in the locale name is ignored; for example, "alic