C Program for Bubble Sort

In this tutorial, we will learn about how to create a program in C that sorts an array in ascending order using bubble sort technique. At last we have also created a function that can be used to sort any given array in ascending order.

But before going through the program, if you are not aware of how bubble sorts works, then refer to the step by step working of Bubble Sort. Now let's move on and implement it in C program.

Bubble Sort in C

Now let's implement bubble sort in a C program as given below. I'll explain each and every line of code later on. The question is, write a program in C that sorts given array in ascending order using Bubble Sort technique. The answer to this question is:

#include<stdio.h>
#include<conio.h>
int main()
{
    int arr[50], i, j, n, temp;
    printf("Enter total number of elements to store: ");
    scanf("%d", &n);
    printf("Enter %d elements:", n);
    for(i=0; i<n; i++)
        scanf("%d", &arr[i]);
    printf("\nSorting array using bubble sort technique...\n");
    for(i=0; i<(n-1); i++)
    {
        for(j=0; j<(n-i-1); j++)
        {
            if(arr[j]>arr[j+1])
            {
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
    printf("All Array elements sorted successfully!\n");
    printf("Array elements in ascending order:\n\n");
    for(i=0; i<n; i++)
        printf("%d ", arr[i]);
    getch();
    return 0;
}

As the above program was written under Code::Blocks IDE, therefore after successful build and run, here is the first snapshot of the sample run:

Now supply size for the array say 10 and then enter 10 array elements. After providing array size and its element, press ENTER key to sort and print all array elements in Ascending order using bubble sort method. Here is the second snapshot of the sample run:

Program Explained

• We have asked from user to enter array size
• Then to enter array elements of that size
• Now for sorting, we have used first (outer) for loop from 0 to (n-1) as array indexing starts from 0 not 1.
• And then second (inner) for loop from 0 to (n-i-1). As we have to compare two consecutive element, and if first element is greater than second, then we have to swap.
• For example, if value of i is 0, then value of j will also be 0, and then using if statement, 0^th element is compared with (0+1)^th or 1^st element. If the element present at 0 will be greater than the element present at 1, then the swapping will be performed.
• The loop will run upto the end that is, if total of 10 elements in the array, then at last the 8^th element will gets compared with (8+1)^th element, that is 9^th element which is the last one.
• After running the loop to check, compare and swap each and every consecutive element (or every j^th to (j+1)^th element), we have sorted the array in ascending order.
• Finally print out the same array that will show all of its element in ascending order

Display Array after Each Sort

If you want to display the array after each sort, then here is the program you may go for:

#include<stdio.h>
#include<conio.h>
int main()
{
    int arr[10], i, j, temp;
    printf("Enter 10 array elements:");
    for(i=0; i<10; i++)
        scanf("%d", &arr[i]);
    for(i=0; i<(10-1); i++)
    {
        for(j=0; j<(10-i-1); j++)
        {
            if(arr[j]>arr[j+1])
            {
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
        printf("\n");
        printf("Step %d: ", i+1);
        for(j=0; j<10; j++)
            printf("%d ", arr[j]);
        printf("\n");
    }
    printf("\nSorted Array is:\n");
    for(i=0; i<10; i++)
        printf("%d ", arr[i]);
    getch();
    return 0;
}

Here is the final snapshot of this program:

Bubble Sort Program in C using Function

Here is another program that does the same job using a user-defined function bubbleSort():

#include<stdio.h>
#include<conio.h>
void bubbleSort(int arr[], int n);
int main()
{
    int arr[100], nos, i;
    printf("How many element that has to be sorted ? ");
    scanf("%d", &nos);
    printf("\n");
    for(i=0; i<nos; i++)
    {
        printf("Enter integer value for element no.%d: ",i+1);
        scanf("%d",&arr[i]);
    }
    bubbleSort(arr, nos);
    printf("\n\nFinally sorted array is:\n");
    for(i=0; i<nos; i++)
        printf("%d\n",arr[i]);
    getch();
    return 0;
}
void bubbleSort(int arr[], int no)
{
    int i, j, temp;
    for(i=no-2; i>=0; i--)
    {
        for(j=0; j<=i; j++)
        {
            if(arr[j]>arr[j+1])
            {
                temp = arr[j];
                arr[j] = arr[j+1];
                arr[j+1] = temp;
            }
        }
    }
}

After successful build and run. Here is the first screenshot of the sample run:

And here is the second screenshot of the sample run:

Program Explained

All the steps are same as discussed in very first program (of this article) except function. As here we have used function to implement bubble sort. Here are some of the main steps that tells how to use function in this case:

• Here we have asked from user to enter array size and then all elements of that size one by one using for loop
• We have passed the array and array size to function. Passing array means passing array elements, here array size that comes in square bracket, example, arr[10] is optional.
• After above two steps, we are at function step. In function, we have used same technique as discussed above, that is comparing each consecutive elements from start to end.
• If first is greater than second, then swap, if second is greater than third then swap and so on.
• But here we have initialized i with (no-1). Here no indicates to total number of element. For example, if total number of element is 10, then i is initialized to 8, and in second loop, j is initialized with 0.
• Then at first run, the j^th element is compared with (j+1)^th element. That is 0^th element is compared with (0+1)^th element (1^st) element. At second run, 1^st element is compared with 2^nd element and so on. This loop will run total of 8 times to compare 8^th element with 9^th element which is the last element.
• After successfully doing all the above steps, the function execution will be over and our array gets sorted in ascending order.
• Now we only have to display the array element with the help of loop

Same Program in Other Languages

• C++ Bubble Sort
• Java Bubble Sort

C Online Test