NOTE: As always, it's better if you don't write your own sorts. Java has better sort methods in java.util.Arrays.sort(...) and java.util.Collections.sort(...). But sorts are excellent practice, and are a technique that all students are expected to understand to some extent.
The Bubble Sort method works like this: In a series of n-1 iterations, the successive elements, list[index] and list[index + 1] of list are compared. If list[index] is greater than list[index + 1], then the elements of list[index] and list[index + 1] are swapped.
This process is repeated through the list until no swaps
are necessary. On average, for a list with length 'n', the Bubble Sort
method takes:
*
key comparisons: (n*(n-1))/2
*
item assignments: (n*(n-1))/4
public class TestBubbleSort {
public static void main(String[] args)
{
int unsortedArray[]
= {10, 97, 6, 23, 0, -45, 697, -1000, 1, 0}; //Random set of numbers for
example.
int i;
bubbleSort(unsortedArray, unsortedArray.length); //Pass the array to be sorted and its length.
System.out.println("After sorting, the list elements are: "); //Just to show you it worked. :)
for(i=0; i<unsortedArray.length;
i++) {
System.out.print(unsortedArray[i] + " ");
}
}
private static void bubbleSort(int[]
unsortedArray, int length) {
int temp,
counter, index;
for(counter=0;
counter<length-1; counter++) { //Loop once for each element in the array.
for(index=0; index<length-1-counter; index++) { //Once for each element,
minus the counter.
if(unsortedArray[index] > unsortedArray[index+1]) { //Test if need a swap
or not.
temp = unsortedArray[index]; //These three lines just swap the two elements:
unsortedArray[index] = unsortedArray[index+1];
unsortedArray[index+1] = temp;
}
}
}
}
}
<-- End of Program -->
