Selection sort

Selection sort is a sort algorithm that works as follows:

remove the lowest datum one at a time until the set of data is empty

The naive algorithm, iterating through a list of n unsorted items, has a worst-case, average-case and best-case run-time of O(n²), assuming that comparisons can be done in constant time.

Heapsort optimizes the algorithm by using a heap data structure to speed up the finding and removing of the lowest datum.

Example

Here is a simple implementation of selection sort in C (from pd lecture notes):

int find_min_index (float [], int, int);
void swap (float [], int, int);
/* selection sort on array v of n floats */
void selection_sort (float v[], int n) {
 int  i;

 /* for i from 0 to n-1, swap v[i] with the minimum
  * of the i'th to the n'th array elements
  */
 for (i=0; i} 
/* find the index of the minimum element of float array v from
* indices start to end
*/
int find_min_index (float v[], int start, int end) {
 int  i, mini;

 mini = start;
 for (i=start+1; i}
/* swap i'th with j'th elements of float array v */
void swap (float v[], int i, int j) {
 float	t;

 t = v[i];
 v[i] = v[j];
 v[j] = t;
}