C#，.NET常见算法

1.递归算法

1.1.C#递归算法计算阶乘的方法

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 阶乘：一个正整数的阶乘Factorial是所有小于以及等于该数的正整数的积，0的阶乘是1，n的阶乘是n！/// </summary>public static void Main(){int result = Factorial(5);Console.WriteLine("5的阶乘是："+result);Console.ReadLine();}private static int Factorial(int v){if(v == 0 || v == 1){return 1;}else{return v * Factorial(v-1);}}}
}

1.2.C#递归算法计算数组的和

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 数组求和/// </summary>public static void Main(){int[] numbers = { 1,2,3,4,5};int sum = ArraySum(numbers,0);Console.WriteLine("数组的和是："+sum);Console.ReadLine();}private static int ArraySum(int[] arr, int v){if(v>=arr.Length){return 0;}else{return arr[v] + ArraySum(arr, v + 1);}}}
}

1.3.C#递归算法实现斐波那契数列第三十位数字

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 实现斐波那契数列的第三十位，已知斐波那契数列1,1,2,3,5,8，自身计算前二个之和/// </summary>public static void Main(){int n = 30;int result = feibonaqi(30);Console.WriteLine("斐波那契数列第三十位是："+result);Console.ReadLine();        }private static int feibonaqi(int v){if(v <= 0){return 0;}else if(v > 0 && v <=2){return 1;}else{return feibonaqi(v - 1) + feibonaqi(v - 2);}}}
}

1.4.C#递归算法计算1-100的和

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 计算1-100-sum/// </summary>public static void Main(){int result = SumNumber(100);Console.WriteLine("1+2+3+4+...+100="+result);Console.ReadLine();        }private static int SumNumber(int v){if(v ==1){return 1;}else{return v + SumNumber(v-1);}}}
}

2.排序算法

2.1.冒泡排序算法

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 双重循环方式实现冒泡排序/// </summary>public static void Main(){int[] arr = { 1,6,4,2,3,9,8,0,7};int arrLength = arr.Length;for(int i =0; i< arr.Length -1; i++){for(int j=0;j<arr.Length-i-1;j++){if(arr[j]>arr[j+1]){int tmp = arr[j];arr[j] = arr[j + 1];arr[j + 1] = tmp;}}}Console.WriteLine("排序后的顺序"+string.Join(",",arr));Console.ReadLine();}}
}

2.2. 使用递归算法实现冒牌排序

using System;namespace C_Sharp_Example
{public class  Program{/// <summary>/// 递归方式实现冒泡排序/// </summary>public static void RecursiveBubbleSort(int[] arr, int arrLength){if (arrLength == 1)return;for(int i=0; i<arrLength-1;i++){if(arr[i] > arr[i+1]){int tmp = arr[i];arr[i] = arr[i + 1];arr[i + 1] = tmp;}}RecursiveBubbleSort(arr,arrLength-1);}private static void RecursiveBubbleSortRun(){int[] arr = { 1,6,4,2,3,9,8,0,7};int arrLength = arr.Length;RecursiveBubbleSort(arr,arrLength);Console.WriteLine("排序后的结果"+string.Join(",",arr));Console.ReadLine();}}
}