public class BubbleSort
3: import java.util.Scanner;
5: /**
6: *
7: * @author Mark Young (A00000000)
8: */
9: public class BubbleSort {
11: public static final Scanner KBD = Common.KBD;
12: private static final int HOW_MANY = 10;
13: private static final int MAX = 1000;
14: private static int traceLevel = 0;
16: public static void main(String[] args) {
17: System.out.println("\n\n"
18: + "Bubble Sort\n"
19: + "===========\n");
21: setTraceLevel();
23: // create an array of random integers
24: int[] numbers = Common.randomNumbers(HOW_MANY, MAX / 10, MAX);
25: Common.printArray(numbers);
26: Common.pause();
28: // sort it
29: bubbleSort(numbers);
30:
31: // show it sorted
32: System.out.println("Array now sorted");
33: Common.printArray(numbers);
34: Common.pause();
35: }
37: /**
38: * Prompt for and read a level of tracing to do.
39: */
40: public static void setTraceLevel() {
41: String traceMenu = "Enter a trace level: \n"
42: + " 0 - no tracing\n"
43: + " 1 - outer loop only\n"
44: + " 2 - inner loop as well\n\n"
45: + "Trace level: ";
47: System.out.print(traceMenu);
48: traceLevel = KBD.nextInt();
49: KBD.nextLine();
50: while (traceLevel < 0 || 2 < traceLevel) {
51: System.out.print(traceMenu);
52: traceLevel = KBD.nextInt();
53: KBD.nextLine();
54: }
55: }
57: /**
58: * Perform bubble sort on the given array.
59: *
60: * @param arr the array to sort
61: */
62: public static void bubbleSort(int[] arr) {
63: String msg;
64: for (int i = arr.length - 1; i > 0; --i) {
65: for (int j = 0; j < i; ++j) {
66: if (traceLevel > 1) {
67: Common.printArray(arr, j, j + 2);
68: }
69: if (arr[j] > arr[j + 1]) {
70: msg = "swap";
71: Common.swap(arr, j, j + 1);
72: } else {
73: msg = "ok";
74: }
75: if (traceLevel > 1) {
76: System.out.println("...." + msg + "....");
77: Common.pause();
78: }
79: }
80: if (traceLevel > 0) {
81: System.out.println("One more bubbled up");
82: Common.printArray(arr, i, arr.length);
83: Common.pause();
84: }
85: }
86: }
88: }