Programmer Think

1. Introduction Graph: directed graph and undirected graphProblem solving steps: (1) Drawing construction: what kind of drawing and how to build it (2) Then, specific problems are analyzed, such as using BFS and greedy algorithm to operate the graph Joint search set //Parallel query set (manage a series of sets that do not want to ...

Boundary value of binary search Binary search is very simple, but it also has its difficulties. The difficulty lies in the selection of judgment conditions and boundary values, which can easily lead to boundary crossing or dead cycle. For the judgment condition of the loop, if the search interval is a closed interval [left, right], the judgme ...

The four questions here have different ideas: The first two are topological sorting. The concept of penetration is used to judge whether there are rings in the graph. Queue and stack are used respectively.When creating a graph, you can use dynamic capacity expansion to build a data structure similar to the adjacency tableThe third problem uses ...

I. 1351. Negative Numbers in Statistically Ordered Matrix 1. Title 1351. Negative numbers in statistical ordered matrices Give you a matrix grid of m * n whose elements are arranged in a non-increasing order, either by row or by column. Please count and return the number of negative numbers in the grid. 2. Analysis The title has ...

Linked list Definition of linked list n nodes are linked into a linked list, which is the linked storage structure of linear list. Because each node of this linked list contains only one pointer field, it is called single linked list. 1. Characteristics of linked list Linked list is not suitable for fast positioning data, and is suitab ...

☘ preface ☘ Today is the seventh day of the nine day training. I will record the learning contents and problem solutions and strive to be the class representative 0.0 Link: LeetCode zero foundation guide (Lecture 8) two dimensional array 🧑🏻 About the author: a young man who changed from industrial design to embedded ✨ Contact: 2201891 ...

Primary algorithm 1, Remove duplicates from sort array Title: give you an ordered array nums. Please delete the repeated elements in place, so that each element appears only once, and return the new length of the deleted array. Do not use additional array space. You must modify the input array in place and complete it with O(1) additional sp ...

55. Minimum stack force buckle (LeetCode) 👉155. Minimum stack force buckle (LeetCode) Topic Description: design push, pop, top and getMin functions, and find the minimum value when the time complexity is O(1) Wrong idea: given a variable to record the minimum value, this idea is wrong, and we should consider the problem more comprehensi ...

807. Maintain the urban skyline 2021.12. 13 one question per day Title Description Give you a city composed of N x n blocks, each block contains a cube building. Give you an n x n integer matrix grid with subscript starting from 0, where grid[r][c] represents the height of the building located in row r and column c. The skyline of a city is ...

The maximum rectangular area of rainwater and histogram are two problems that echo each other. There are many similarities in principle, but there are differences in details. Connected to rainwater (monotonous stack) Brute force method (double pointer): Note that after finding the highest column on the left and right sides, it is also ne ...