Binary Search, Bubble Sort, and Selection Sort in C++

Since the lectures in this unit use Python for illustration, review these examples in C++.

Binary search:

#include <stdio.h>
 
int main()
{
   int c, first, last, middle, n, search, array[100];
 
   printf("Enter number of elements\n");
   scanf("%d",&n);
 
   printf("Enter %d integers\n", n);
 
   for (c = 0; c < n; c++)
      scanf("%d",&array[c]);
 
   printf("Enter value to find\n");
   scanf("%d", &search);
 
   first = 0;
   last = n - 1;
   middle = (first+last)/2;
 
   while (first <= last) {
      if (array[middle] < search)
         first = middle + 1;    
      else if (array[middle] == search) {
         printf("%d found at location %d.\n", search, middle+1);
         break;
      }
      else
         last = middle - 1;
 
      middle = (first + last)/2;
   }
   if (first > last)
      printf("Not found! %d is not present in the list.\n", search);
 
   return 0;   
}

Selection sort:

#include <stdio.h>
 
int main()
{
   int array[100], n, c, d, position, swap;
 
   printf("Enter number of elements\n");
   scanf("%d", &n);
 
   printf("Enter %d integers\n", n);
 
   for ( c = 0 ; c < n ; c++ )
      scanf("%d", &array[c]);
 
   for ( c = 0 ; c < ( n - 1 ) ; c++ )
   {
      position = c;
 
      for ( d = c + 1 ; d < n ; d++ )
      {
         if ( array[position] > array[d] )
            position = d;
      }
      if ( position != c )
      {
         swap = array[c];
         array[c] = array[position];
         array[position] = swap;
      }
   }
 
   printf("Sorted list in ascending order:\n");
 
   for ( c = 0 ; c < n ; c++ )
      printf("%d\n", array[c]);
 
   return 0;
}

Bubble sort:

/* Bubble sort code */
 
#include <stdio.h>
 
int main()
{
  int array[100], n, c, d, swap;
 
  printf("Enter number of elements\n");
  scanf("%d", &n);
 
  printf("Enter %d integers\n", n);
 
  for (c = 0; c < n; c++)
    scanf("%d", &array[c]);
 
  for (c = 0 ; c < ( n - 1 ); c++)
  {
    for (d = 0 ; d < n - c - 1; d++)
    {
      if (array[d] > array[d+1]) /* For decreasing order use < */
      {
        swap       = array[d];
        array[d]   = array[d+1];
        array[d+1] = swap;
      }
    }
  }
 
  printf("Sorted list in ascending order:\n");
 
  for ( c = 0 ; c < n ; c++ )
     printf("%d\n", array[c]);
 
  return 0;
}

Bubble sort using a function

#include <stdio.h>
 
void bubble_sort(long [], long);
 
int main()
{
  long array[100], n, c, d, swap;
 
  printf("Enter number of elements\n");
  scanf("%ld", &n);
 
  printf("Enter %ld integers\n", n);
 
  for (c = 0; c < n; c++)
    scanf("%ld", &array[c]);
 
  bubble_sort(array, n);
 
  printf("Sorted list in ascending order:\n");
 
  for ( c = 0 ; c < n ; c++ )
     printf("%ld\n", array[c]);
 
  return 0;
}
 
void bubble_sort(long list[], long n)
{
  long c, d, t;
 
  for (c = 0 ; c < ( n - 1 ); c++)
  {
    for (d = 0 ; d < n - c - 1; d++)
    {
      if (list[d] > list[d+1])
      {
        /* Swapping */
 
        t         = list[d];
        list[d]   = list[d+1];
        list[d+1] = t;
      }
    }
  }
}

Source: Programming Simplified, http://www.programmingsimplified.com/c/source-code/c-program-binary-search,  http://www.programmingsimplified.com/c/source-code/c-program-selection-sort, and http://www.programmingsimplified.com/c/source-code/c-program-bubble-sort
Creative Commons License This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Last modified: Monday, November 16, 2020, 8:13 PM