Table Of Contents

**Sorting** :Sorting refers to arranging data in a particular format. Sorting algorithm specifies the way to arrange data in a particular order. Most common orders are in numerical or lexicographical order.

**Telephone Directory** − The telephone directory stores the telephone numbers of people sorted by their names, so that the names can be searched easily.

**Dictionary −** The dictionary stores words in an alphabetical order so that searching of any word becomes easy.

For example, suppose we have a record of students, every such record will have the following data:

Roll No.

Name

Age

Class

**Types of Sorting Techniques**

There are many types of Sorting techniques, differentiated by their efficiency and space requirements. Following are some sorting techniques which we will be covering in next sections.

**Bubble Sort**

**Insertion Sort**

**Selection Sort**

**Quick Sort**

**Merge Sort**

**Heap Sort**

**How Bubble Sort Works?**

We take an unsorted array for our example. Bubble sort takes Ο(n2) time so we’re keeping it short and precise.

Bubble sort starts with very first two elements, comparing them to check which one is greater.

In this case, value 33 is greater than 14, so it is already in sorted locations. Next, we compare 33 with 27.

We find that 27 is smaller than 33 and these two values must be swapped.

The new array should look like this −

Next we compare 33 and 35. We find that both are in already sorted positions.

Then we move to the next two values, 35 and 10.

We know then that 10 is smaller 35. Hence they are not sorted.

We swap these values. We find that we have reached the end of the array. After one iteration, the array should look like this −

To be precise, we are now showing how an array should look like after each iteration. After the second iteration, it should look like this −

Notice that after each iteration, at least one value moves at the end.

And when there’s no swap required, bubble sorts learns that an array is completely sorted.

Now we should look into some practical aspects of bubble sort.

We assume list is an array of n elements. We further assume that swap function swaps the values of the given array elements.

**Selection Sorting**

for(int i=0; i<4; i++) { for(int j=0; j<4; j++) { if(array[j]>array[j+1]) { temp=array[j+1]; array[j+1]=array[j]; array[j]=temp; } } }

**Bubble Sorting**

for (int i = 0; i < 4; i++) for (int j = i; j < 4; j++) if (data[i] > data[j+1]) { tmp = data[j+1]; data[j+1]=data[i]; data[i] = tmp; }

**Bubble sorting in Linked List**

void sorting() { for(temp=start;temp->ptr!=NULL;temp=temp->ptr) { for(temp1=start;temp1->ptr!=NULL;temp1=temp1->ptr) { if(temp1->data > temp1->ptr->data) { int temp2=temp1->data; temp1->data=temp1->ptr->data; temp1->ptr->data=temp2; }}}}

**Selection sorting in Linked List**

void sorting() { for(temp=start;temp->ptr!=NULL;temp=temp->ptr) { for(temp1=temp->ptr;temp1!=NULL;temp1=temp1->ptr) { if(temp->data > temp1->data) { int tmp; tmp=temp->data; temp->data=temp1->data; temp1->data=tmp; }}}}