0 array 1 2 3 4 bubble sort example 73 42 11 58 5

0
array
1
2
3
4
Bubble Sort Example
73
42
11
58
5
Spring 2022 Sacramento State - Cook - CSc 130 22
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
73
42
58
11
5
Spring 2022 Sacramento State - Cook - CSc 130 23
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
73
11
58
42
5
Spring 2022 Sacramento State - Cook - CSc 130 24
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
42
11
58
73
5
Spring 2022 Sacramento State - Cook - CSc 130 25
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
42
11
58
73
5
Spring 2022 Sacramento State - Cook - CSc 130 26
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
73
58
42
11
Spring 2022 Sacramento State - Cook - CSc 130 27
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
42
58
73
11
Spring 2022 Sacramento State - Cook - CSc 130 28
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
42
58
11
73
Spring 2022 Sacramento State - Cook - CSc 130 29
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
11
58
73
42
Spring 2022 Sacramento State - Cook - CSc 130 30
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
11
42
73
58
Spring 2022 Sacramento State - Cook - CSc 130 31
Outer Loop
Inner Loop

0
array
1
2
3
4
Bubble Sort Example
5
11
42
73
58
Spring 2022 Sacramento State - Cook - CSc 130 32
Outer Loop
Inner Loop

 The Bubble Sort is extremely inefficient and only
good for tiny arrays
 Since Bubble Sort uses two embedded loops
• the outer loop looks at all n items
• the inner loop looks at basically n items
• the resulting algorithm gets exponentially less efficient
as n increases
Efficiency of the Bubble Sort
Spring 2022 Sacramento State - Cook - CSc 130 33

Efficiency of the Bubble Sort
Spring 2022 Sacramento State - Cook - CSc 130 34
 The Bubble Sort O(n 2 )
 … two embedded loops that
are based on n
 … and all that swapping
doesn't help either!

Bubble Sort
Time Average O(n 2 )
Time Best O(n
2
)
Time Worst O(n
2
)
Auxiliary space O(1)
Stable Yes – Equal element order preserved
Online? No – Entire array in use
Spring 2022 Sacramento State - Cook - CSc 130 35
Bubble Sort Summary

Selection Sort
The Human Way

 The Selection Sort is a similar
to the Bubble Sort
 However…
• rather than "bubble up" smaller
items, it scans the entire array
• it finds the smallest element
• only then does it swap the
values
Selection Sort
Spring 2022 Sacramento State - Cook - CSc 130 37

 Like the Bubble Sort, it consists of two For Loops –
one outer and one inner
 Outer loop runs from the first to the last
 Inner loop …
• starts at the position of the outer loop
• scans down and finds the smallest value
 Then, after the scan, do a single swap
Selection Sort
Spring 2022 Sacramento State - Cook - CSc 130 38

for( i = 0; i < count-1; i++ )
{
best = i ;
for( j = i ; j < count; j++ )
{
if (array[ j ] < array[ best ])
{
best = j ;
}
}
//swap array[i] and array[ best ]
}
The Selection Sort
Spring 2022 Sacramento State - Cook - CSc 130 39

Selection Sort Example
Spring 2022 Sacramento State - Cook - CSc 130 40
0
array
1
2
3
4
73
42
11
58
5
Outer Loop
Inner Loop

Selection Sort Example: New Best
Spring 2022 Sacramento State - Cook - CSc 130 41
0
array
1
2
3
4
73
42
11
58
5
Outer Loop
Inner Loop