Facebook Page Twitter Page LinkedIn Page
× C Examples


Bubble sort is the simplest sorting algorithm. The Bubble sort is based on the idea that every adjacent elements are compared and swapped if found in wrong order.

Example:

To understand the bubble sort, lets consider an unsorted array [1, 23, 10, -2] and discuss each step taken to sort the array in ascending order. In every pass, two adjacent elements are checked and swapped if found in wrong order.

First Pass: (1) and (23) are compared and found in correct order(ascending order in this case). After that (23) and (10) are compared, since (23>10), hence these numbers are swapped. Then (23) and (-2) are compared and swapped.

Second Pass: (1) and (10) are compared and found in correct order. Then (10) and (-2) are compared, since (10>-2), hence these numbers are swapped. After that (10) and (23) are compared and found in correct order.

Third Pass: (1) and (-2) are compared, since (1>-2), hence these numbers are swapped. After that (1,10) and (10,23) are checked and found in correct order.

Bubble Sort

Implementation of Bubble Sort

#include <stdio.h>

// function for bubble sort
static void bubblesort(int Array[], int n) {
  int temp;
  for(int i=0; i<n; i++) {
    for(int j=0; j<n-i-1; j++) {
      if(Array[j]>Array[j+1]) {
        temp = Array[j];
        Array[j] = Array[j+1];
        Array[j+1] = temp;
      }
    }
  }
}

// function to print array
static void PrintArray(int Array[], int n) { 
  for (int i=0; i<n; i++)  
    printf("%i ",Array[i]); 
  printf("\n"); 
} 

// test the code
int main () {
  int MyArray[] = {1, 10, 23, 50, 4, 9, -4};
  int n = sizeof(MyArray) / sizeof(MyArray[0]); 
  printf("Original Array\n");
  PrintArray(MyArray, n);

  bubblesort(MyArray, n);
  printf("\nSorted Array\n");
  PrintArray(MyArray, n);
  return 0;
}

The above code will give the following output:

Original Array
1 10 23 50 4 9 -4 

Sorted Array
-4 1 4 9 10 23 50 

Time Complexity:

The time complexity of bubble sort is Θ(N²) in all cases even if the whole array is sorted because the entire array need to be iterated for every element and it contains two nested loops.