我已经创建了数组和对数组进行排序的方法,但我仍然坚持如何在数组中实现二进制搜索方法。还需要从主类的数组中调用二分查找方法。
public class Search {
public static boolean binarySearch(int[] array, int value) {
return binarySearchHelper(array, value, 0, array.length);
}
private static boolean binarySearchHelper(int[] array, int value, int low, int high) {
if (low <= high) {
int mid = (low + high) / 2;
if (value == array[mid]) {
return true;
} else if (value < array[mid]) {
return binarySearchHelper(array, value, low, mid - 1);
} else {
return binarySearchHelper(array, value, mid + 1, high);
}
}
return false;
}
public static boolean linearSearch(int[] array, int value) {
for (int i = 0; i < array.length; i++) {
if (array[i] == value) {
return true;
} else if (array[i] > value) {
return false;
}
}
return false;
}
这是主要的
import java.util.Random;
import java.util.Arrays;
public class Test {
public static void main(String[] args) {
//System.nanoTime() will give me the current time (it's like looking at the clock)
//I'll save the current time right (immediately) before I start the thing I want to time
long start = System.nanoTime();
long elapsed = System.nanoTime() - start;
Random value = new Random();
int size = 2000;
int max = 5000;
int[] array = new int[size];
for (int i = 0; i < size; i++) {
array[i] = value.nextInt();
}
Arrays.sort(array);
for (int i = 100; i < 2000; i+=100) {
start = System.nanoTime();
for ( int j = 0; j < 2000; j++){
Search.binarySearch(array, value.nextInt());
}
}
elapsed = System.nanoTime() - start;
System.out.println("Total time elapsed is: "+ elapsed);
}
}