search2.java

来自「这是有关电子商务的学习笔记以及java的源代码,非常精彩」· Java 代码 · 共 30 行

public class Search
  {
  static int binarysearch(int a[],int key)
    {
    int left=0;
    int right=a.length-1;
    int middle;
    while (left<=right)
      {
      middle=(left+right)/2
      if (key==a[middle]) return middle;
      else if (key<a[middle]) right=middle-1;
           else left=middle+1;
      }
    return -1;
    }

    public static void main(String args[])
    {
    int a[]={25,36,47,32,21,16};
    int key=Integer.parseInt(args[0]);
    int k=binarysearch(a,key);
    if (k!=-1)
      System.out.println(k);
    else
      System.out.println("not found");
      
    }
  }