6-16 编程练习题答案

import java.util.Arrays;public class Test{public static void main(String[] args){int[] numbers = new int[100000];for(int i = 0; i < 100000; i++)numbers[i] = (int)(Math.random() * 100000);int key = (int)(Math.random() * 100000);long startTime = System.currentTimeMillis();System.out.println(linearSearch(numbers, key));long endTime = System.currentTimeMillis();long executionTime = endTime - startTime;System.out.println("The linearSearch has spent " + executionTime + " milliseconds");Arrays.sort(numbers);startTime = System.currentTimeMillis();System.out.println(binarySearch(numbers, key));endTime = System.currentTimeMillis();executionTime = endTime - startTime;System.out.println("The linearSearch has spent " + executionTime + " milliseconds");}public static int linearSearch(int[] list, int key){for(int i = 0; i < list.length; i++)if(key == list[i])return i;return -1;}public static int binarySearch(int[] list, int key){int low = 0;int high = list.length - 1;while(high >= low){int mid = (low + high) / 2;if(key < list[mid])high = mid - 1;else if(key == list[mid])return mid;elselow = mid + 1;}return -low - 1;}}