Sort algorithm bubble sort (Java)



The bubbling sort is each traversal. The adjacent numbers are compared, the former is larger than the latter, and the maximum value is shifted back to the last position; The key point of the algorithm is to determine the boundary of each cycle;

The following two algorithms are a certain degree of improvement to bubble sort, but the bubble sort performance is still poor compared with other sorting algorithms.

Bubble sort public class Bubble_sort {//The original solution public void Bubble_sort1 (int[] data) {int n = data.length;for (int i = 0; i < n; i++) {//Note the index range of the loop to avoid overflow for (int j = 0; J < n-i-1, j + +) {if (Data[j] > data[j + 1]) {Swap (data, J, j + 1);}}} Improved algorithm, by introducing a flag to determine whether a loop has a movement, if no move, then//the order has been completed, do not need to continue the next cycle public void Bubble_sort2 (int[] data) {int n = Data.length;boolean flag = true;//Indicates whether moving int index = n-1; Mark the last one that needs to be cycled//once in motion, continue looping while (flag) {flag = false;for (int j = 0; J < Index-1; J + +) {if (data[j] > Dat A[j + 1]) {Swap (data, J, j + 1); flag = True;}} index--;}} Improved algorithm two: When a traversal, the last m-bit is not converted, it means that the next n-bit is larger than the current maximum number//According to the bubble sort, each sink into the maximum, then these bits must have been ordered public void Bubble_sort3 (int[] data) { int n = Data.length;int index = n-1;while (Index! = 0) {int k = 0;for (int j = 0; J < Index-1; J + +) {if (Data[j] > Da Ta[j + 1]) {Swap (data, J, j + 1); k = j;}} index = k;}} Cannot use reference implementations like C + +, so it has to be changed with the data array private void Swap (int[] data, int a, int b) {int temp = Data[a];d ata[a] = data[b];d ata[b] = temP;} public void Print_array (int[] data) {for (int num:data) {System.out.print (num); System.out.print ("");}} public static void Main (string[] args) {Bubble_sort bubble_sort = new Bubble_sort (); int data[] = {2,34,45,2,13,24,5,24,57} ; bubble_sort.bubble_sort3 (data); Bubble_sort.print_array (data);}}

Sort algorithm bubble sort (Java)