Bubble Sort

Bubble sort

How it works;
Basically bubble sort works by stepping through the data a swapping the current and next data items if they are out of order.

Properties;
Best case and worst case speed are both O(n^2)
Memory is 1 (the temp swap location)

//compile with g++
#include <iostream>
#include <iomanip>
using namespace std;

void print(int data[], int size);

void bubblesort(int data[], int size)
{
  bool change = true;
  int tmp;
  while(change)
    {
      change = false;
      for(int i = 0;i < size-1;i++)
        if(data[i] > data[i+1])
          {
            tmp = data[i];
            data[i] = data[i+1];
            data[i+1] = tmp;
            change = true;
          }
    }
}

//test
#define SIZE 20
#define SCRAMBLE(x, y) ((0xa57b & ~y) + ((0x3829 & x) << 1))

bool check(int data[], int size)
{
  for(int i = 1; i < size; i++)
    if(data[i] < data[i-1])
      {
        cout << "FAIL!" << endl;
        return false;
      }
  cout << "PASS" << endl;
  return true;
}

void print(int data[], int size)
{
  for(int i = 0; i < size; i++)
    cout << setw(5) << data[i] << " ";
  cout << endl;
}

bool test(int data[], int size)
{
  print(data, SIZE);
  bubblesort(data,SIZE);
  print(data, SIZE);
  return check(data, SIZE);
}

int main()
{
  int data[SIZE];
  bool pass = true;

  //easy data
  data[0] = 1;
  for(int i = 0; i < SIZE; i++)
    data[i] = SIZE - i;
  pass &= test(data, SIZE);

  //semi repeated data
  data[0] = 1;
  for(int i = 0; i < SIZE; i++)
    data[i] = SCRAMBLE(i, data[i-1]);
  pass &= test(data, SIZE);

  //the sort killer!
  for(int i = 0; i < SIZE; i++)
    data[i] = 5;
  pass &= test(data, SIZE);

  //and some randoms to catch anything i missed
  srand ( time(NULL) );

  for(int j = 0; j < 100; j++)
    {
      for(int i = 0; i < SIZE; i++)
        data[i] = (int)((float)(j+1)*((float)rand()/(float)RAND_MAX));
      pass &= test(data, SIZE);
    }

  if(pass)
    cout << "ALL PASSED" << endl;
  else
    cout << "FAILED" << endl;
}