单词接龙算法:如何找到两个单词之间的最短变换路径

算法 专栏收录该内容
¥59.90 ¥99.00
51篇文章

单词接龙是一种有趣的游戏,其目标是通过逐步变换单词中的一个字母,从起始单词变换到目标单词。在这篇文章中,我们将探讨如何使用广度优先搜索算法来找到两个单词之间的最短变换路径。

广度优先搜索(BFS)是一种图搜索算法,它从给定的起始节点开始,逐层遍历其相邻节点,直到找到目标节点为止。在单词接龙问题中,我们可以将每个单词看作图中的一个节点,并且两个单词之间存在边(即变换一个字母得到另一个单词)。我们的目标是找到从起始单词到目标单词的最短路径,即最少的变换步骤。

让我们来看看如何实现这个算法。

首先,我们需要构建一个单词字典,用于快速查找一个单词是否存在。我们可以使用一个哈希集合来实现这个字典。

def build_word_dict(word_list):
    word_dict = set()
    for
【leetcode热题】单词接龙 II 如果余下的单词的规模为 N,每个单词的长度为 M,时间复杂度为 O(NM)。另外一种思路是对当前单词进行变换,然后在单词聚合中查询是否存在,这种方法需要查询 26*(M-1) 次散列表,当单词表很大时,这个方法比前一种方法快很多。这样在寻找到终点时,就可以不断地向前查询,直到起点。提前构造图时没有必要的,要想提前造图,需要对各个单词两两计算差异,但在遍历的随着余下的节点的规模减小,计算量也会慢慢下降。可以将所有单词视作图中的节点,两个词语之间如果相差的字符为 1,在图中这两个词之间就存在一条路径。 阅读详情

相关推荐

Leetcode 单词接龙

特性单词接龙(Word Ladder)最小基因变化(Min Mutation)起始 step1(包括起点)0(只计变换次数)变化字符集'a'到'z'共 26 个字母4 种碱基每轮字符数组构建方式每次新建char[]修改原数组char[],需回溯目标不存在的返回值0-1是否需要手动回溯❌ 不需要✅ 需要。

985小菜鸡 920

谁说“单词接龙”只是游戏?从图论角度搞定最短变换路径!

本文从图论角度重新审视单词接龙游戏,将其建模为最短路径问题。通过将每个单词视为节点、仅差一个字母的单词之间建立边,将问题转化为图的广度优先搜索(BFS)。文章提出通配符映射法优化建图效率,从O(N²)降至O(N×L),并展示了该模型在自然语言处理、基因分析等领域的实际应用价值。核心观点强调算法思维在于将现实问题抽象为数学模型(如用图表示单词关系),再用搜索方法(BFS)高效解决,揭示了算法建模的本质魅力。

Echo_Wish 99

leetcode单词接龙2-Algorithms:算法学习笔记

leetcode单词接龙2 Algorithms 算法学习笔记 目录 leetcode刷题笔记 数组 排序算法 链表 反转 关系题型整理 股票买卖 矩形面积或装水问题 子序列问题 排列组合 栈 队列 树 基础遍历 BFS DFS 回溯 动态规划

声音事件检测metric:PSDS

这项工作为多声道声音事件检测(SED)系统的性能评估定义了一个新的框架,它克服了传统的collar-based事件决定、事件F-cores和事件错误率的限制。拟议的框架引入了对事件检测的定义,该定义对标签的主观性更为稳健。它还采用了多声道接收器操作特性(ROC)曲线,以提供比F1分数更全面的系统性能洞察力,并建议将这些曲线简化为单一的多声道声音检测分数(PSDS),这允许系统独立于操作点(OPs)进行比较。所提出的方法还能更好地了解不同声音类别的数据偏差和分类稳定性。

Maestro_T的博客 2728

完整的申请邓白氏编码的流程(手把手教你申请邓白氏编码)

申请公司的苹果开发者账号和企业级的苹果开发者账号时,都会用到邓白氏编码,也就是我们申请苹果开发者账号时需要填写的D-U-N-S Number。     申请这个邓白氏编码是免费的,但是从像华夏邓白氏公司提交申请到可以申请苹果开发者账号来用这个9位的D-U-N-S Number,需要一段时间,我申请得到D-U-N-S Number,用了8个工作日(不算周末哦)

wxw2011014003的博客 9万+

从轻量化到高精度:3DXML 转 STP 的工程数据升级技术指南

本文详细解析了3DXML转STP格式的工程数据升级技术,对比了两种格式在轻量化和高精度方面的特性差异,并提供了CATIA、FreeCAD及Python编程等多种专业级转换方案。通过实际案例展示了如何确保转换过程中的数据精度,适用于CAD设计、精密制造等场景,帮助工程师实现工程数据的高效升级。

weixin_29201859的博客 215

必看!wechat-article-exporter:轻松批量下载公众号文章

微信搜索“”关注公众号。在信息爆炸的时代,我们每天都会接触到大量优秀的微信公众号文章。有时候,我们想要将这些精彩的内容保存下来,以便日后回顾或者分享给更多的人。然而,微信公众号并没有提供直接的批量下载功能,这给我们带来了不少困扰。今天,我要给大家分享一款非常实用的软件——wechat-article-exporter,它能够帮助我们轻松地批量下载微信公众号文章,让你不再为文章的保存而烦恼。

王乐平 技术博客 4351

Wordpress实战之第二章安装wordpress 软件需要的软件

使用下载并安装phpstudy面版工具 wget -O install.sh?https://notdocker.xp.cn/install.sh?&& sudo bash install.sh 2.安装成功如下 ==============运行状态========================= webpanel stop phpstudy running =================...

安全参透之旅 611

15、基于最优传输的协作多视图聚类框架

本文提出了一种基于最优传输理论的协作多视图聚类框架,通过引入协作学习机制在不同视图间建立先验交互,以提升共识聚类的质量。框架包含两种新方法:协作共识投影方法(CoCP)和基于新表示的协作共识方法(CoCNR)。CoCP在全局空间中整合多视图信息并进行共识投影,而CoCNR则通过协作编码生成新的数据表示以实现更优聚类。方法利用熵正则化的Wasserstein距离与Wasserstein重心,有效捕捉数据分布间的几何结构,并通过聚合步骤获得统一模型。实验结果表明,所提方法在多个数据集上均优于现有方法,具有良好的

gpt4scribbler的博客 85

数据分析!Python爬虫爬取B站UP主数据并分析涨粉规律(附可视化图表)

爬取更多UP主:扩充列表,增加需要分析的UP主UID数量爬取更多作品:修改的参数,增加每个UP主的作品爬取页数新增分析维度:在类中添加方法,可分析发布时间(如定时发布对涨粉的影响)、内容标签(如游戏/知识区涨粉差异)优化可视化样式:调整方法中的图表类型、颜色、标题等,适配个人展示需求播放量与粉丝数强正相关:从相关性热力图可看出,总播放量与粉丝数的相关系数通常在0.8以上,说明曝光量是涨粉的核心基础作品数量存在“边际效应”

专注于Python爬虫开发,分享爬虫技巧、项目实战与反爬经验,使用Scrapy、BeautifulSoup等工具,解决数据抓取难题。 1225

深度学习工具包 DeepLearningToolbox

深度学习工具包Deprecation notice.-----This toolbox is outdated and no longer maintained.There are much better tools available for deep learning than this toolbox, e.g. [Theano](http://deeplearning.net/software/theano/), [torch](http://torch.ch/) or [tensorflow](http://www.tensorflow.org/)I would suggest you use one of the tools mentioned above rather than use this toolbox.Best, Rasmus.DeepLearnToolbox================A Matlab toolbox for Deep Learning.Deep Learning is a new subfield of machine learning that focuses on learning deep hierarchical models of data.It is inspired by the human brain's apparent deep (layered, hierarchical) architecture.A good overview of the theory of Deep Learning theory is[Learning Deep Architectures for AI](http://www.iro.umontreal.ca/~bengioy/papers/ftml_book.pdf)For a more informal introduction, see the following videos by Geoffrey Hinton and Andrew Ng.* [The Next Generation of Neural Networks](http://www.youtube.com/watch?v=AyzOUbkUf3M) (Hinton, 2007)* [Recent Developments in Deep Learning](http://www.youtube.com/watch?v=VdIURAu1-aU) (Hinton, 2010)* [Unsupervised Feature Learning and Deep Learning](http://www.youtube.com/watch?v=ZmNOAtZIgIk) (Ng, 2011)If you use this toolbox in your research please cite [Prediction as a candidate for learning deep hierarchical models of data](http://www2.imm.dtu.dk/pubdb/views/publication_details.php?id=6284)```@MASTERSTHESIS\{IMM2012-06284, author = "R. B. Palm", title = "Prediction as a candidate for learning deep hierarchical models of data", year = "2012",}```Contact: rasmusbergpalm at gmail dot comDirectories included in the toolbox-----------------------------------`NN/` - A library for Feedforward Backpropagation Neural Networks`CNN/` - A library for Convolutional Neural Networks`DBN/` - A library for Deep Belief Networks`SAE/` - A library for Stacked Auto-Encoders`CAE/` - A library for Convolutional Auto-Encoders`util/` - Utility functions used by the libraries`data/` - Data used by the examples`tests/` - unit tests to verify toolbox is workingFor references on each library check REFS.mdSetup-----1. Download.2. addpath(genpath('DeepLearnToolbox'));Example: Deep Belief Network---------------------```matlabfunction test_example_DBNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit RBM and visualize its weightsrand('state',0)dbn.sizes = [100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);figure; visualize(dbn.rbm{1}.W'); % Visualize the RBM weights%% ex2 train a 100-100 hidden unit DBN and use its weights to initialize a NNrand('state',0)%train dbndbn.sizes = [100 100];opts.numepochs = 1;opts.batchsize = 100;opts.momentum = 0;opts.alpha = 1;dbn = dbnsetup(dbn, train_x, opts);dbn = dbntrain(dbn, train_x, opts);%unfold dbn to nnnn = dbnunfoldtonn(dbn, 10);nn.activation_function = 'sigm';%train nnopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.10, 'Too big error');```Example: Stacked Auto-Encoders---------------------```matlabfunction test_example_SAEload mnist_uint8;train_x = double(train_x)/255;test_x = double(test_x)/255;train_y = double(train_y);test_y = double(test_y);%% ex1 train a 100 hidden unit SDAE and use it to initialize a FFNN% Setup and train a stacked denoising autoencoder (SDAE)rand('state',0)sae = saesetup([784 100]);sae.ae{1}.activation_function = 'sigm';sae.ae{1}.learningRate = 1;sae.ae{1}.inputZeroMaskedFraction = 0.5;opts.numepochs = 1;opts.batchsize = 100;sae = saetrain(sae, train_x, opts);visualize(sae.ae{1}.W{1}(:,2:end)')% Use the SDAE to initialize a FFNNnn = nnsetup([784 100 10]);nn.activation_function = 'sigm';nn.learningRate = 1;nn.W{1} = sae.ae{1}.W{1};% Train the FFNNopts.numepochs = 1;opts.batchsize = 100;nn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.16, 'Too big error');```Example: Convolutional Neural Nets---------------------```matlabfunction test_example_CNNload mnist_uint8;train_x = double(reshape(train_x',28,28,60000))/255;test_x = double(reshape(test_x',28,28,10000))/255;train_y = double(train_y');test_y = double(test_y');%% ex1 Train a 6c-2s-12c-2s Convolutional neural network %will run 1 epoch in about 200 second and get around 11% error. %With 100 epochs you'll get around 1.2% errorrand('state',0)cnn.layers = { struct('type', 'i') %input layer struct('type', 'c', 'outputmaps', 6, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %sub sampling layer struct('type', 'c', 'outputmaps', 12, 'kernelsize', 5) %convolution layer struct('type', 's', 'scale', 2) %subsampling layer};cnn = cnnsetup(cnn, train_x, train_y);opts.alpha = 1;opts.batchsize = 50;opts.numepochs = 1;cnn = cnntrain(cnn, train_x, train_y, opts);[er, bad] = cnntest(cnn, test_x, test_y);%plot mean squared errorfigure; plot(cnn.rL);assert(er<0.12, 'Too big error');```Example: Neural Networks---------------------```matlabfunction test_example_NNload mnist_uint8;train_x = double(train_x) / 255;test_x = double(test_x) / 255;train_y = double(train_y);test_y = double(test_y);% normalize[train_x, mu, sigma] = zscore(train_x);test_x = normalize(test_x, mu, sigma);%% ex1 vanilla neural netrand('state',0)nn = nnsetup([784 100 10]);opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samples[nn, L] = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.08, 'Too big error');%% ex2 neural net with L2 weight decayrand('state',0)nn = nnsetup([784 100 10]);nn.weightPenaltyL2 = 1e-4; % L2 weight decayopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex3 neural net with dropoutrand('state',0)nn = nnsetup([784 100 10]);nn.dropoutFraction = 0.5; % Dropout fraction opts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex4 neural net with sigmoid activation functionrand('state',0)nn = nnsetup([784 100 10]);nn.activation_function = 'sigm'; % Sigmoid activation functionnn.learningRate = 1; % Sigm require a lower learning rateopts.numepochs = 1; % Number of full sweeps through dataopts.batchsize = 100; % Take a mean gradient step over this many samplesnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex5 plotting functionalityrand('state',0)nn = nnsetup([784 20 10]);opts.numepochs = 5; % Number of full sweeps through datann.output = 'softmax'; % use softmax outputopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, train_x, train_y, opts);[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');%% ex6 neural net with sigmoid activation and plotting of validation and training error% split training data into training and validation datavx = train_x(1:10000,:);tx = train_x(10001:end,:);vy = train_y(1:10000,:);ty = train_y(10001:end,:);rand('state',0)nn = nnsetup([784 20 10]); nn.output = 'softmax'; % use softmax outputopts.numepochs = 5; % Number of full sweeps through dataopts.batchsize = 1000; % Take a mean gradient step over this many samplesopts.plot = 1; % enable plottingnn = nntrain(nn, tx, ty, opts, vx, vy); % nntrain takes validation set as last two arguments (optionally)[er, bad] = nntest(nn, test_x, test_y);assert(er < 0.1, 'Too big error');```[![Bitdeli Badge](https://d2weczhvl823v0.cloudfront.net/rasmusbergpalm/deeplearntoolbox/trend.png)](https://bitdeli.com/free "Bitdeli Badge")

OV9734 DATASHEET,完整规格书

OV9734完整规格书,包括电气参数,尺寸规格,寄存器配置表等

Devexpress16.2.6破解工具

Devexpress16.2.6破解工具Devexpress16.2.6破解工具Devexpress16.2.6破解工具Devexpress16.2.6破解工具

Data-Structures-and-Algorithm-Analysis-in-Java.pdf

作者: Weiss, Mark A. 出版社: Addison Wesley Data Structures and Algorithm Analysis in Java is an “advanced algorithms” book that fits between traditional CS2 and Algorithms Analysis courses. In the old ACM Curriculum Guidelines, this course was known as CS7. This text is for readers who want to learn good programming and algorithm analysis skills simultaneously so that they can develop such programs with the maximum amo...

上一篇: 整数反转算法详解
下一篇: 最小无序连续子数组的算法实现
普通网友
博客等级 码龄3年 3粉丝 0原创
评论 1
成就一亿技术人!
拼手气红包6.0元
还能输入1000个字符  | 博主筛选后可见
 
 条评论被折叠 查看
添加红包

请填写红包祝福语或标题

个

红包个数最小为10个

元

红包金额最低5元

当前余额3.43元 前往充值 >
需支付:10.00元
成就一亿技术人!
领取后你会自动成为博主和红包主的粉丝 规则
hope_wisdom
发出的红包
实付元
使用余额支付
点击重新获取
扫码支付
钱包余额 0

抵扣说明:

1.余额是钱包充值的虚拟货币,按照1:1的比例进行支付金额的抵扣。
2.余额无法直接购买下载,可以购买VIP、付费专栏及课程。

余额充值