package com.zc.manythread; import java.util.Random; import java.util.Scanner; /**  *  * @author 偶my耶  *    循环查找  *    二元查找  */ public class LinearSearch {     //循序搜索     public static int LinearSearch(int[] list,int item)     {         for(int i = 0 ; i < list.length;i++)         {             if(list[i]==item)                 return i;//找到传回的位置         }         return -1;//找不到时     }     //二元搜寻,传入的数先排序好,由小至大     public static int BinarySearch(int[] list,int item)     {         //初始左右二边         int left = 0 ;         int right = list.length;         //左边的索引位置小于右边的索引的位置         while(left<=right)         {             int mid = (left + right)/2;             if(list[mid]==item)                 return mid;             else             {                 //所查询值比中间值小,故值会在中间的左边数列                 if(list[mid]>item)                 {                     right = mid -1;                 }else                 {                     left = mid +1;                 }             }         }         return -1;//找不到时     }     /**      * 产生随机数组      * @param count      * @return      */     private static int[]  createDate(int count) {         int[] data=new int[count];           Random rand = new Random();           boolean[] bool = new boolean[100];           int num = 0;           for (int i = 0; i < count; i++) {            do {             // 如果产生的数相同继续循环             num = rand.nextInt(100);            } while (bool[num]);            bool[num] = true;            data[i]=num;           }           return data;     }     public static void main(String args[])     {         //输入要查找的数         Scanner in = new Scanner(System.in);         //循序搜寻案列         int[] list = createDate(10);         System.out.println("原始数列:");         for(int i = 0 ; i <list.length ; i ++)         {             System.out.print(list[i]+" ");         }         System.out.println("\r\n请输入要查询的数:");         int searchkey = in.nextInt();         int ans =  LinearSearch(list,searchkey);         if(ans>-1)         {             System.out.println("找到数,位置在:"+(ans+1)+"位");         }         else             System.out.println("找不着");         //二元搜寻案列         int[] list2 = {2,4,6,8,10,12,13,14,15,16};         System.out.println("原始数据:");         for(int i = 0 ; i<list2.length ; i ++)         {             System.out.print(list2[i]+" ");         }         System.out.println("\r\n请输入要查询的数:");         int searchkey2 = in.nextInt();         int ans2 =  BinarySearch(list2,searchkey2);         if(ans2>-1)         {             System.out.println("找到数,位置在:"+ans2+"位");         }         else             System.out.println("找不着!");     } }