Bubble sort is one of the simplest and most popular algorithms, but inefficient. It repeatedly compares each element with their adjacent elements and performs swapping if required.

Pseudocode

FOR i=0 to Array.Length
FOR j=Array.Length-1 to i
IF A[j]< A[j-1])
Swap A[j] and A[j-1]
END IF
END FOR
END FOR

C program to sort an array using Bubble Sort in Ascending Order

#include<conio.h>
#include<stdio.h>
#define size 5
void main()
{
int arr[size],i,j,temp;
printf("Please enter elements: \n "); 
for(i=0;i<=size-1;i++)
{
scanf("%d",&arr[i]);
}

for(i=0;i<=size-1;i++)
{
for(j=size-1;j>i;j--)
{
if(arr[j]<arr[j-1]){
temp = arr[j];
arr[j] =arr[j-1];
arr[j-1] = temp;
}

}

}

printf(" \n Entered Elements :");

for(i=0;i<=size-1;i++)
{
printf("\n %d ",arr[i]);
} 
getch();

}

Output:

How does Bubble Sort program work?

It requires a constant amount O(1) of additional memory space and O(n²) comparisons in the worst case and average case to sort an array.

However, this sorting technique is too slow and impractical if we compare it with Insertion sort