Three ways of traversing trees and their breadth

Algorithmic Base-Tree Three ways to traverse a tree (recursive) The three recursive traversals of trees are based on recursive order. The so-called recursive order is that each node returns to that node three times if it uses recursion. For example: The so-called recursive order is that each node traverses three times, so when using recursion ...

Posted by verdrm on Sun, 07 Nov 2021 08:02:43 -0800

Codeforces 103389j maximum weight edge independent set

Maximum weighted edge independent set It's really a hand speed field. It belongs to yes. I can only say that I'm lucky. No wa, Jinwei Laishui blog At that time, there was a mistake. Of course, some strings were unfamiliar. When I saw J, I felt like a tree dp. Although I couldn't figure out the details in the game, the general direction ...

Posted by PhaZZed on Sat, 06 Nov 2021 23:04:38 -0700

Summary of basic algorithms

Bit operation Pilot brother Title Link Problem solving ideas: Each switch of the chessboard has two states: on or off, so the total number of States is 2 16 2^{16} 216. The range of int is not ...

Posted by thallium6 on Sat, 06 Nov 2021 18:01:47 -0700

SP6779 GSS7 - Can you answer these queries VII

Title Link: SP6779 GSS7 - Can you answer these queries VII General meaning Given a tree with n n A tree with n nodes, each node has a weight w i ( ...

Posted by Ghost_81st on Sat, 06 Nov 2021 13:27:50 -0700

Week 1 algorithm learning and sorting

Weekly summary of algorithm practice (10.31-11.6) Learning objectives: One week elementary practice of algorithm Learning content: 1. Question: call fee calculation 2. Problem: time conversion 3. Problem: Abbreviated summation 4. Problem: word encryption 5. Problem: monkeys eat peaches Study time: 1. 7 p.m. - 9 p.m. from Monday to ...

Posted by SieRobin on Sat, 06 Nov 2021 13:05:49 -0700

Manually tear the minimum heap (rebuild heap + insert data + delete data code explanation + example)

Recommended blog and video explanation Heap sort (heap rebuild + insert + delete detailed explanation) UP Master: bald girl Wang pushed Forward citation I didn't get up until 10 o'clock today. I really don't know why I got up late. Of course, it's also the weekend, but I still have to do things when I got up so late. In the da ...

Posted by pagie on Sat, 06 Nov 2021 10:44:39 -0700

The decision tree picks the watermelon

1, ID3 algorithm 1. Ladle import numpy as np import pandas as pd import sklearn.tree as st import math import matplotlib import os import matplotlib.pyplot as plt 2. Read data data = pd.read_csv('C:/Watermelon dataset.csv',header=None) data 3. Coding entropy def calcEntropy(dataSet): mD = len(dataSet) dataLabelList = [x[-1] f ...

Posted by CWebguy on Sat, 06 Nov 2021 10:26:57 -0700

Merge sort algorithm - C++

The main idea of merge sort algorithm is to merge two ordered arrays into an ordered array. Its key point adopts the "divide and conquer idea". The "divide" is a dichotomy, which divides the unordered array into ordered arrays, and then through the "divide and conquer"   Merge two ordered arrays into one orde ...

Posted by matvespa on Sat, 06 Nov 2021 10:08:50 -0700

Code clipping algorithm for line segment

Code clipping algorithm for line segment For example, many uneven straight-line segments are distributed on a canvas, and we want to find a rectangular window on the canvas and only want to get the straight-line segments in the rectangular window. How should we achieve this? We know that the straight line segment can be expressed by a para ...

Posted by Jeyush on Fri, 05 Nov 2021 23:45:29 -0700

[ye shisan] summary of the most complete knowledge of data structure and algorithm

Brain map: https://www.processon.com/mindmap/6179408f0e3e7416bdeb81d1 development environment Mac C locale configuration Software: Visual Studio Code Coder Runner plug-in 1, Overview of data structures 1. Definition How do we save a large number of complex problems in reality to the main memory (memory) with specific data type ...

Posted by High_-_Tek on Fri, 05 Nov 2021 22:34:06 -0700