Selection Sort

• Algorithms Lesson 8: Selection Sort

http://www.youtube.com/watch?v=6nDMgr0-Yyo&feature=relmfu

• Selection Sort

In computer science, a selection sort is a sorting algorithm, specifically an in-place comparison sort. It has O(n2) time complexity, making it inefficient on large lists, and generally performs worse than the similar insertion sort. Selection sort is noted for its simplicity, and also has performance advantages over more complicated algorithms in certain situations, particularly where auxiliary memory is limited.

The algorithm works as follows:
Find the minimum value in the list
Swap it with the value in the first position
Repeat the steps above for the remainder of the list (starting at the second position and advancing each time)


/* a[0] to a[n-1] is the array to sort */
int i,j;
int iMin;

/* advance the position through the entire array */
/*   (could do j < n-1 because single element is also min element) */
for (j = 0; j < n-1; j++) {
    /* find the min element in the unsorted a[j .. n-1] */

    /* assume the min is the first element */
    iMin = j;
    /* test against elements after j to find the smallest */
    for ( i = j+1; i < n; i++) {
        /* if this element is less, then it is the new minimum */
        if (a[i] < a[iMin]) {
            /* found new minimum; remember its index */
            iMin = i;
        }
    }

    /* iMin is the index of the minimum element. Swap it with the current position */
    if ( iMin != j ) {
        swap(a[j], a[iMin]);
    }
}


http://en.wikipedia.org/wiki/Selection_sort

• Selection Sort

https://www.youtube.com/watch?v=f8hXR_Hvybo

• Algorithms #3 - Selection Sort

https://www.youtube.com/watch?v=TW3_7cD9L1A