Cycle Sort

Cycle sort is a comparison sorting algorithm which forces array to be factored into the number of cycles where each of them can be rotated to produce a sorted array. It is theoretically optimal in the sense that it reduces the number of writes to the original array.

Algorithm

Consider an array of n distinct elements. An element a is given, index of a can be calculated by counting the number of elements that are smaller than a.

if the element is found to be at its correct position, simply leave it as it is.
Otherwise, find the correct position of a by counting the total number of elements that are less than a. where it must be present in the sorted array. The other element b which is replaced is to be moved to its correct position. This process continues until we got an element at the original position of a.

The illustrated process constitutes a cycle. Repeating this cycle for each element of the list. The resulting list will be sorted.

C program

#include<stdio.h>
void sort(int a[], int n)
{
    int writes = 0,start,element,pos,temp,i;
 
    for (start = 0; start <= n - 2; start++) {
        element = a[start];
        pos = start;
        for (i = start + 1; i < n; i++)
            if (a[i] < element)
                pos++;
        if (pos == start)
            continue;
        while (element == a[pos])
            pos += 1;
        if (pos != start) {
            //swap(element, a[pos]);
	    temp = element;
	    element = a[pos];
            a[pos] = temp;  
            writes++;
        }
        while (pos != start) {
            pos = start;
            for (i = start + 1; i < n; i++)
                if (a[i] < element)
                    pos += 1;
            while (element == a[pos])
                pos += 1;
            if (element != a[pos]) {
              temp = element;
	      element = a[pos];
              a[pos] = temp;  
                writes++;
            }
        }
    }
 
 }
 
int main()
{
    int a[] = {1, 9, 2, 4, 2, 10, 45, 3, 2};
    int n = sizeof(a) / sizeof(a[0]),i;
    sort(a, n);
    printf("After sort, array : ");
    for (i = 0; i < n; i++)
        printf("%d	",a[i]);
    return 0;
}

Output:

After sort, array :
1
2
2
2
3
4
9
10
45

Java Program

public class CycleSort 
{
static void sort(int a[], int n)
{
    int writes = 0,start,element,pos,temp,i;
 
    for (start = 0; start <= n - 2; start++) {
        element = a[start];
        pos = start;
        for (i = start + 1; i < n; i++)
            if (a[i] < element)
                pos++;
        if (pos == start)
            continue;
        while (element == a[pos])
            pos += 1;
        if (pos != start) {
            //swap(element, a[pos]);
	    temp = element;
	    element = a[pos];
            a[pos] = temp;  
            writes++;
        }
        while (pos != start) {
            pos = start;
            for (i = start + 1; i < n; i++)
                if (a[i] < element)
                    pos += 1;
            while (element == a[pos])
                pos += 1;
            if (element != a[pos]) {
              temp = element;
	      element = a[pos];
              a[pos] = temp;  
                writes++;
            }
        }
    }
}
public static void main(String[] args)
{
    int a[] = { 1, 9, 2, 4, 2, 10, 45, 3, 2 };
    int n = a.length,i;
    sort(a, n);
    System.out.println("After sort, array : ");
    for (i = 0; i < n; i++)
        System.out.println(a[i]);
    
}
}

Output:

After sort, array :
1
2
2
2
3
4
9
10
45

C# Program

using System;
public class CycleSort 
{
static void sort(int[] a, int n)
{
    int writes = 0,start,element,pos,temp,i;
 
    for (start = 0; start <= n - 2; start++) {
        element = a[start];
        pos = start;
        for (i = start + 1; i < n; i++)
            if (a[i] < element)
                pos++;
        if (pos == start)
            continue;
        while (element == a[pos])
            pos += 1;
        if (pos != start) {
            //swap(element, a[pos]);
	    temp = element;
	    element = a[pos];
            a[pos] = temp;  
            writes++;
        }
        while (pos != start) {
            pos = start;
            for (i = start + 1; i < n; i++)
                if (a[i] < element)
                    pos += 1;
            while (element == a[pos])
                pos += 1;
            if (element != a[pos]) {
              temp = element;
	      element = a[pos];
              a[pos] = temp;  
                writes++;
            }
        }
    }
}
public void Main()
{
    int[] a = { 1, 9, 2, 4, 2, 10, 45, 3, 2  };
    int n = a.Length,i;
    sort(a, n);
    Console.WriteLine("After sort, array : ");
    for (i = 0; i < n; i++)
        Console.WriteLine(a[i]);
    
}
}

Output:

After sort, array :
1
2
2
2
3
4
9
10
45

Next TopicTim Sort

← prev next →

Please Share

Learn Latest Tutorials

Spark

Swift

Pig

Flask

C. Graphics

Preparation

Aptitude

Reasoning

Verbal A.

Interview

B.Tech / MCA

DBMS

DAA

C. Network

Compiler D.

COA

D. Math.

E. Hacking

Web Tech.

Cyber Sec.

Automata

C++

Java

.Net

Python

Programs

Control S.

Javatpoint Services

JavaTpoint offers too many high quality services. Mail us on hr@javatpoint.com, to get more information about given services.

Website Designing
Website Development
Java Development
PHP Development
WordPress
Graphic Designing
Logo
Digital Marketing
On Page and Off Page SEO
PPC
Content Development
Corporate Training
Classroom and Online Training
Data Entry

Training For College Campus

JavaTpoint offers college campus training on Core Java, Advance Java, .Net, Android, Hadoop, PHP, Web Technology and Python. Please mail your requirement at hr@javatpoint.com.
Duration: 1 week to 2 week

^{Like/Subscribe us for latest updates or newsletter}