Animation to show how selection sort works
The below example shows selection sort in Python
def sort_selection(my_list):
for pos_upper in xrange( len(my_list)-1, 0, -1):
max_pos = 0
for i in xrange(1, pos_upper + 1):
if(my_list[i] > my_list[max_pos]):
max_pos = i
print "resetting max_pos = " + str(max_pos)
my_list[pos_upper], my_list[max_pos] = my_list[max_pos], my_list[pos_upper]
print "pos_upper: " + str(pos_upper) + " max_pos: " + str(max_pos) + " my_list: " + str(my_list)
return my_list
if __name__ == "__main__":
my_list = [54,26,93,17,77,31,44,55,20]
print "my_list: " + str(my_list)
print sort_selection(my_list)
Output of the program:
my_list: [54, 26, 93, 17, 77, 31, 44, 55, 20]
resetting max_pos = 2
pos_upper: 8 max_pos: 2 my_list: [54, 26, 20, 17, 77, 31, 44, 55, 93]
resetting max_pos = 4
pos_upper: 7 max_pos: 4 my_list: [54, 26, 20, 17, 55, 31, 44, 77, 93]
resetting max_pos = 4
pos_upper: 6 max_pos: 4 my_list: [54, 26, 20, 17, 44, 31, 55, 77, 93]
pos_upper: 5 max_pos: 0 my_list: [31, 26, 20, 17, 44, 54, 55, 77, 93]
resetting max_pos = 4
pos_upper: 4 max_pos: 4 my_list: [31, 26, 20, 17, 44, 54, 55, 77, 93]
pos_upper: 3 max_pos: 0 my_list: [17, 26, 20, 31, 44, 54, 55, 77, 93]
resetting max_pos = 1
pos_upper: 2 max_pos: 1 my_list: [17, 20, 26, 31, 44, 54, 55, 77, 93]
resetting max_pos = 1
pos_upper: 1 max_pos: 1 my_list: [17, 20, 26, 31, 44, 54, 55, 77, 93]
[17, 20, 26, 31, 44, 54, 55, 77, 93]
Image Reference: Pirate Learner