C++ Example – Bubble Sort Algorithm

August 11, 2016 admin C++ 0

The bubble sort Algorithm simply compares adjacent elements and exchanges them if they are out of order.

To apply the Bubble Sort we follow the following steps.

Compare 1st two elements and exchange them if they are out of order.
Move down one element and compare 2nd and 3rd elements. Exchange if necessary. Continue until end of array.
Pass through array again, repeating process and exchanging as necessary.
Repeat until a pass is made with no exchanges.

In this lesson we will learn how to write a source code in C++ programming language for doing simple bubble sort using array in ascending order.

#include <iostream>

void PrintArray(int *array, int n) {
  for (int i = 0; i < n; ++i)
    std::cout << array[i] << " " << std::flush;
  std::cout << std::endl;
}

void BubbleSort(int *array, int n) {
  bool swapped = true;
  int j = 0;
  int temp;

  while (swapped) {
    swapped = false;
    j++;
    for (int i = 0; i < n - j; ++i) {
      if (array[i] > array[i + 1]) {
        temp = array[i];
        array[i] = array[i + 1];
        array[i + 1] = temp;
        swapped = true;
      }
    }
  }
}

int main() {
  int array[] = {94, 42, 50, 95, 333, 65, 54, 456, 1, 1234};
  int n = sizeof(array)/sizeof(array[0]);

  std::cout << "Before Bubble Sort :" << std::endl;
  PrintArray(array, n);

  BubbleSort(array, n);

  std::cout << "After Bubble Sort :" << std::endl;
  PrintArray(array, n);
  return (0);
}


/*
OUTPUT
Before Bubble Sort :
94 42 50 95 333 65 54 456 1 2325
After Bubble Sort :
1 42 50 54 65 94 95 333 456 2325
*/