HW6.16

 1 import java.util.Arrays;
 2 
 3 public class Solution
 4 {
 5     public static void main(String[] args)
 6     {
 7         int[] array1 = new int[10000];
 8         int[] array2 = new int[10000];
 9 
10         for(int i = 0; i < 10000; i++)
11         {
12             array1[i] = (int)(Math.random() * 100);
13             array2[i] = (int)(Math.random() * 100);
14         }
15 
16         int sign1 = (int)(Math.random() * 100);
17         int sign2 = (int)(Math.random() * 100);
18 
19         System.out.println("Array1 run time: " + linearRunTime(array1, sign1));
20         System.out.println("Array2 run time: " + binaryRunTime(array2, sign2));
21     }
22 
23     public static long linearRunTime(int[] array, int number)
24     {
25         long startTime = System.currentTimeMillis();
26         linearSearch(array, number);
27         long endTime = System.currentTimeMillis();
28         long executionTime = endTime - startTime;
29         return executionTime;
30     }
31 
32     public static long binaryRunTime(int[] array, int number)
33     {
34         Arrays.sort(array);
35         long startTime = System.currentTimeMillis();
36         binarySearch(array, number);
37         long endTime = System.currentTimeMillis();
38         long executionTime = endTime - startTime;
39         return executionTime;
40     }
41 
42     public static void linearSearch(int[] array, int number)
43     {
44         for(int i = 0; i < array.length; i++)
45             if(number == array[i])
46                 return;
47     }
48 
49     public static void binarySearch(int[] array, int number)
50     { binarySearch(array, number, 0, array.length - 1); }
51 
52     public static void binarySearch(int[] array, int number, int low, int high)
53     {
54         if(low < high)
55             return;
56         int mid = (low + high) / 2;
57         if(number < array[mid])
58             binarySearch(array, number, low, mid);
59         else if(number > array[mid])
60             binarySearch(array, number, mid + 1, high);
61         else if(number == array[mid])
62             return;
63     }
64 }