前言
算法在计算机科学和程序设计中扮演着至关重要的角色，如在解决问题、优化效率、决策优化、实现计算机程序、提高可靠性以及促进科学融合等方面具有广泛而深远的影响。今天大姚给大家分享一个开源、免费、全面的C#算法实战教程：TheAlgorithms/C-Sharp。
项目介绍
一个C#实现的各种算法集合，这些算法涵盖了计算机科学、数学和统计学、数据科学、机器学习、工程等多个领域。这些实现及其相关文档旨在为教育工作者和学生提供学习资源。因此，可能会找到针对同一目标使用不同算法策略和优化的多种实现。
项目源代码
主要算法包括
- 排序算法：冒泡排序、插入排序、计数排序、快速排序等
- 搜索算法：线性搜索、二分搜索等
- 数值计算：最大公约数、二项式系数、牛顿的平方根计算、欧拉方法等
- 字符串算法：Rabin-Karp 算法、KMP 算法、Manacher 算法等
- 数据结构：链表 (Linked List)、栈 (Stack)、队列 (Queue)、二叉树 (Binary Tree)等
- 图算法：深度优先搜索 (Depth-First Search)、广度优先搜索 (Breadth-First Search)、Dijkstra 最短路径等
- 等等......
插入排序
/// <summary> /// Class that implements insertion sort algorithm. /// </summary> /// <typeparam name="T">Type of array element.</typeparam> public class InsertionSorter<T> : IComparisonSorter<T> { /// <summary> /// Sorts array using specified comparer, /// internal, in-place, stable, /// time complexity: O(n^2), /// space complexity: O(1), /// where n - array length. /// </summary> /// <param name="array">Array to sort.</param> /// <param name="comparer">Compares elements.</param> public void Sort(T[] array, IComparer<T> comparer) { for (var i = 1; i < array.Length; i++) { for (var j = i; j > 0 && comparer.Compare(array[j], array[j - 1]) < 0; j--) { var temp = array[j - 1]; array[j - 1] = array[j]; array[j] = temp; } } } }
快速排序
/// <summary> /// Sorts arrays using quicksort. /// </summary> /// <typeparam name="T">Type of array element.</typeparam> public abstract class QuickSorter<T> : IComparisonSorter<T> { /// <summary> /// Sorts array using Hoare partition scheme, /// internal, in-place, /// time complexity average: O(n log(n)), /// time complexity worst: O(n^2), /// space complexity: O(log(n)), /// where n - array length. /// </summary> /// <param name="array">Array to sort.</param> /// <param name="comparer">Compares elements.</param> public void Sort(T[] array, IComparer<T> comparer) => Sort(array, comparer, 0, array.Length - 1); protected abstract T SelectPivot(T[] array, IComparer<T> comparer, int left, int right); private void Sort(T[] array, IComparer<T> comparer, int left, int right) { if (left >= right) { return; } var p = Partition(array, comparer, left, right); Sort(array, comparer, left, p); Sort(array, comparer, p + 1, right); } private int Partition(T[] array, IComparer<T> comparer, int left, int right) { var pivot = SelectPivot(array, comparer, left, right); var nleft = left; var nright = right; while (true) { while (comparer.Compare(array[nleft], pivot) < 0) { nleft++; } while (comparer.Compare(array[nright], pivot) > 0) { nright--; } if (nleft >= nright) { return nright; } var t = array[nleft]; array[nleft] = array[nright]; array[nright] = t; nleft++; nright--; } } }
线性搜索
/// <summary> /// Class that implements linear search algorithm. /// </summary> /// <typeparam name="T">Type of array element.</typeparam> public class LinearSearcher<T> { /// <summary> /// Finds first item in array that satisfies specified term /// Time complexity: O(n) /// Space complexity: O(1). /// </summary> /// <param name="data">Array to search in.</param> /// <param name="term">Term to check against.</param> /// <returns>First item that satisfies term.</returns> public T Find(T[] data, Func<T, bool> term) { for (var i = 0; i < data.Length; i++) { if (term(data[i])) { return data[i]; } } throw new ItemNotFoundException(); } /// <summary> /// Finds index of first item in array that satisfies specified term /// Time complexity: O(n) /// Space complexity: O(1). /// </summary> /// <param name="data">Array to search in.</param> /// <param name="term">Term to check against.</param> /// <returns>Index of first item that satisfies term or -1 if none found.</returns> public int FindIndex(T[] data, Func<T, bool> term) { for (var i = 0; i < data.Length; i++) { if (term(data[i])) { return i; } } return -1; } }
项目源码地址
更多项目实用功能和特性欢迎前往项目开源地址查看👀，别忘了给项目一个Star支持💖。
GitHub开源地址：https://github.com/TheAlgorithms/C-Sharp
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