Csharp/C Sharp/Collections Data Structure/Sort

A simple version of the Quicksort

<source lang="csharp"> /* C# A Beginner"s Guide By Schildt Publisher: Osborne McGraw-Hill ISBN: 0072133295

• /

// A simple version of the Quicksort.

using System;

class Quicksort {

 // Set up a call to the actual Quicksort method. 
 public static void qsort(char[] items) { 
   qs(items, 0, items.Length-1); 
 } 

 // A recursive version of Quicksort for characters. 
 static void qs(char[] items, int left, int right)  
 {  
   int i, j;  
   char x, y;  
 
   i = left; j = right;  
   x = items[(left+right)/2];  
 
   do {  
     while((items[i] < x) && (i < right)) i++;  
     while((x < items[j]) && (j > left)) j--;  
 
     if(i <= j) {  
       y = items[i];  
       items[i] = items[j];  
       items[j] = y;  
       i++; j--;  
     }  
   } while(i <= j);  
 
   if(left < j) qs(items, left, j);  
   if(i < right) qs(items, i, right);  
 } 

}

public class QSDemo {

 public static void Main() { 
   char[] a = { "d", "x", "a", "r", "p", "j", "i" }; 
   int i; 

   Console.Write("Original array: "); 
   for(i=0; i < a.Length; i++)  
     Console.Write(a[i]); 

   Console.WriteLine(); 

   // now, sort the array 
   Quicksort.qsort(a); 
    
   Console.Write("Sorted array: "); 
   for(i=0; i < a.Length; i++)  
     Console.Write(a[i]); 
 } 

}

      </source>

Bubble sort

<source lang="csharp"> using System;

 delegate bool Comparator(object lhs, object rhs);
 class MainEntryPoint {
   static void Main() {
     Employee [] employees = {
             new Employee("A", 20000),
             new Employee("B", 10000),
             new Employee("C", 25000),
             new Employee("D", 99999),
             new Employee("E", 23000),
             new Employee("F", 50000)};
             
     BubbleSorter.Sort(employees, new Comparator(Employee.IsGreater));
     for (int i=0 ; i<employees.Length ; i++){
       Console.WriteLine(employees[i].ToString());
     }  
   }
 }
 class Employee {
   private string name;
   private decimal salary;
   public Employee(string name, decimal salary)
   {
     this.name = name;
     this.salary = salary;
   }
   public override string ToString()
   {
     return string.Format(name + ", {0:C}", salary);
   }
   public static bool IsGreater(object a, object b)
   {
     Employee empA = (Employee) a;
     Employee empB = (Employee) b;
     return (empA.salary > empB.salary) ? true : false;
   }
 }
 class BubbleSorter
 {
   static public void Sort(object [] sortArray, Comparator gtMethod) {
     for (int i=0 ; i<sortArray.Length ; i++) {
       for (int j=i+1 ; j<sortArray.Length ; j++) {
         if (gtMethod(sortArray[j], sortArray[i])) {
           object temp = sortArray[i];
           sortArray[i] = sortArray[j];
           sortArray[j] = temp;
         }
       }
     }
   }
 }
          
      </source>

Demonstrate the Bubble sort

<source lang="csharp"> /* C# A Beginner"s Guide By Schildt Publisher: Osborne McGraw-Hill ISBN: 0072133295

• /

/*

  Project 5-1 
  Demonstrate the Bubble sort. 

• /

using System;

public class BubbleSort {

 public static void Main() {  
   int[] nums = { 99, -10, 100123, 18, -978, 
                  5623, 463, -9, 287, 49 }; 
   int a, b, t;  
   int size;  
 
   size = 10; // number of elements to sort  
 
   // display original array  
   Console.Write("Original array is:"); 
   for(int i=0; i < size; i++) 
     Console.Write(" " + nums[i]);  
   Console.WriteLine();  
 
   // This is the bubble sort.  
   for(a=1; a < size; a++)  
     for(b=size-1; b >= a; b--) {  
       if(nums[b-1] > nums[b]) { // if out of order  
         // exchange elements   
         t = nums[b-1];  
         nums[b-1] = nums[b];  
         nums[b] = t;  
       }  
     }  
 
   // display sorted array  
   Console.Write("Sorted array is:");  
   for(int i=0; i < size; i++) 
     Console.Write(" " + nums[i]);  
   Console.WriteLine(); 
 } 

}

      </source>

Implements the recursive merge sort algorithm to sort an array

<source lang="csharp"> using System; public class MergeSort {

 public static void Sort (int[] data, int left, int right) {
   if (left < right) {
     int middle = (left + right)/2;
     Sort(data, left, middle);
     Sort(data, middle + 1, right);
     Merge(data,left, middle, middle+1, right);
   }
 }
 public static void Merge(int[] data, int left, int middle, int middle1, int right) {
   int oldPosition = left;
   int size = right - left + 1;
   int[] temp = new int[size];
   int i = 0;  
   
   while (left <= middle && middle1 <= right) {
     if (data[left] <= data[middle1]) 
       temp[i++] = data[left++];
     else
       temp[i++] = data[middle1++];
   }
   if (left > middle) 
     for (int j = middle1; j <= right; j++)
       temp[i++] = data[middle1++];
   else
     for (int j = left; j <= middle; j++)
       temp[i++] = data[left++];
   Array.Copy(temp, 0, data, oldPosition, size);
 }
 
 public static void Main (String[] args) {
   int[] data = new int[]{2,3,1,6,2,98,4,6,4,3,45};
   
   for (int i = 0; i < data.Length; i++) { 
     Console.WriteLine(data[i]);
   }
   Sort(data, 0, data.Length-1);
   for (int i = 0; i < data.Length; i++) { 
     Console.WriteLine(data[i]);
   }
 }

}

      </source>

Sorts an array of data using the insertion sort algorithm

<source lang="csharp"> using System; public class InsertionSort {

 public static void InsertNext(int i, int[] item) {
   int current = item[i];
   int j = 0;
   while (current > item[j]) j++;
   for (int k = i; k > j; k--)
     item[k] = item[k-1];
   item[j] = current;
 }
 public static void Sort(int[] item) {
   for (int i = 1; i < item.Length; i++) {
     InsertNext(i, item); 
   }
 }
 public static void Main()  {
   int[] item = new int[]{2,4,1,6,3,8,1,0,2,6,3,6};
   Sort(item);
   for(int i=0; i<item.Length;i++){
       Console.WriteLine(item[i]);
   }
 }

}

      </source>