数据结构和算法

DSA - 主页 DSA - 概述 DSA - 环境设置 DSA - 算法基础 DSA - 渐近分析

数据结构

DSA - 数据结构基础 DSA - 数据结构和类型 DSA - 数组数据结构

链接列表

DSA - 链接列表数据结构 DSA - 双向链接列表数据结构 DSA - 循环链表数据结构

堆栈 &队列

DSA - 堆栈数据结构 DSA - 表达式解析 DSA - 队列数据结构

搜索算法

DSA - 搜索算法 DSA - 线性搜索算法 DSA - 二分搜索算法 DSA - 插值搜索 DSA - 跳跃搜索算法 DSA - 指数搜索 DSA - 斐波那契搜索 DSA - 子列表搜索 DSA - 哈希表

排序算法

DSA - 排序算法 DSA - 冒泡排序算法 DSA - 插入排序算法 DSA - 选择排序算法 DSA - 归并排序算法 DSA - 希尔排序算法 DSA - 堆排序 DSA - 桶排序算法 DSA - 计数排序算法 DSA - 基数排序算法 DSA - 快速排序算法

图形数据结构

DSA - 图形数据结构 DSA - 深度优先遍历 DSA - 广度优先遍历 DSA - 生成树

树数据结构

DSA - 树数据结构 DSA - 树遍历 DSA - 二叉搜索树 DSA - AVL 树 DSA - 红黑树 DSA - B树 DSA - B+ 树 DSA - 伸展树 DSA - 尝试 DSA - 堆数据结构

递归

DSA - 递归算法 DSA - 使用递归的汉诺塔 DSA - 使用递归的斐波那契数列

分而治之

DSA - 分而治之 DSA - 最大最小问题 DSA - 施特拉森矩阵乘法 DSA - Karatsuba 算法

贪婪算法

DSA - 贪婪算法 DSA - 旅行商问题(贪婪方法) DSA - Prim 最小生成树 DSA - Kruskal 最小生成树 DSA - Dijkstra 最短路径算法 DSA - 地图着色算法 DSA - 分数背包问题 DSA - 作业排序截止日期 DSA - 最佳合并模式算法

动态规划

DSA - 动态规划 DSA - 矩阵链乘法 DSA - Floyd Warshall 算法 DSA - 0-1 背包问题 DSA - 最长公共子序列算法 DSA - 旅行商问题(动态方法)

近似算法

DSA - 近似算法 DSA - 顶点覆盖算法 DSA - 集合覆盖问题 DSA - 旅行商问题(近似方法)

随机算法

DSA - 随机算法 DSA - 随机快速排序算法 DSA - Karger 最小割算法 DSA - Fisher-Yates 洗牌算法

DSA 有用资源

DSA - 问答 DSA - 快速指南 DSA - 有用资源 DSA - 讨论


Data Structures & Algorithms - Overview

What is Data Structure?

Data Structure is a systematic way to organize data in order to use it efficiently. Following terms are the foundation terms of a data structure.

  • Interface − Each data structure has an interface. Interface represents the set of operations that a data structure supports. An interface only provides the list of supported operations, type of parameters they can accept and return type of these operations.

  • Implementation − Implementation provides the internal representation of a data structure. Implementation also provides the definition of the algorithms used in the operations of the data structure.

Types of Data Structures

Here are different type of data structures which we are going to learn in this tutorial:

What is Algorithm?

Algorithm is a step-by-step procedure, which defines a set of instructions to be executed in a certain order to get the desired output. Algorithms are generally created independent of underlying languages, i.e. an algorithm can be implemented in more than one programming language.

Types of Algorithms

Here are different type of algorithms which we are going to learn in this tutorial:

Characteristics of a Data Structure

  • Correctness − Data structure implementation should implement its interface correctly.

  • Time Complexity − Running time or the execution time of operations of data structure must be as small as possible.

  • Space Complexity − Memory usage of a data structure operation should be as little as possible.

Execution Time Cases

There are three cases which are usually used to compare various data structure's execution time in a relative manner.

  • Worst Case − This is the scenario where a particular data structure operation takes maximum time it can take. If an operation's worst case time is ƒ(n) then this operation will not take more than ƒ(n) time where ƒ(n) represents function of n.

  • Average Case − This is the scenario depicting the average execution time of an operation of a data structure. If an operation takes ƒ(n) time in execution, then m operations will take mƒ(n) time.

  • Best Case − This is the scenario depicting the least possible execution time of an operation of a data structure. If an operation takes ƒ(n) time in execution, then the actual operation may take time as the random number which would be maximum as ƒ(n).

Basic DSA Terminologies

  • Data − Data are values or set of values.

  • Data Item − Data item refers to single unit of values.

  • Group Items − Data items that are divided into sub items are called as Group Items.

  • Elementary Items − Data items that cannot be divided are called as Elementary Items.

  • Attribute and Entity − An entity is that which contains certain attributes or properties, which may be assigned values.

  • Entity Set − Entities of similar attributes form an entity set.

  • Field − Field is a single elementary unit of information representing an attribute of an entity.

  • Record − Record is a collection of field values of a given entity.

  • File − File is a collection of records of the entities in a given entity set.