Java入门：基础算法之线性搜索

Posted 2020-07-04 盆古开天地

本程序使用线性搜索算法从n个数中查找一个数。

/* Program: 线性搜索示例
 * @author: 理工云课堂
 * Input: 元素个数，每个元素值，待查找数据的值
 * Output:待查找数的位置*/
import java.util.Scanner;
class LinearSearchExample
{
   public static void main(String args[])
   {
      int counter, num, item, array[];
      //捕获用户输入
      Scanner input = new Scanner(System.in);
      System.out.println("Enter number of elements:");
      num = input.nextInt(); 
      //创建一个数组来存放所有整数
      array = new int[num]; 
　　　　
      System.out.println("Enter " + num + " integers");
      //循环将用户输入的数存放到数组中
      for (counter = 0; counter < num; counter++)
        array[counter] = input.nextInt();

      System.out.println("Enter the search value:");
      item = input.nextInt();

      for (counter = 0; counter < num; counter++)
      {
         if (array[counter] == item) 
         {
           System.out.println(item+" is present at location "+(counter+1));
           /*找到了这个数就停止查找，使用break终止for循环。*/
           break;
         }
      }
      if (counter == num)
        System.out.println(item + " doesn‘t exist in array.");
   }
}

输出1：

Enter number of elements:
6
Enter 6 integers
22
33
45
1
3
99
Enter the search value:
45
45 is present at location 3

输出2：

Enter number of elements:
4
Enter 4 integers
11
22
4
5
Enter the search value:
99
99 doesn‘t exist in array.