java之旅 折半查找实现

java之旅 折半查找实现

import java.util.Scanner;
public class array{
	public static void main(String[] args){
		

		int[] nums = {4,5,7,11,22,34};//折半查找的前提条件是有序数列
		int result = BinarySearch(nums,22);
		System.out.println(result);
		
	}
	public static int BinarySearch(int[] num,int key){
		int bigin,end,middle;
		bigin = 0;
		end = num.length-1;
		
		while(end>=bigin){
			middle = (end+bigin)/2;
			if(num[middle]key)
				end = middle-1;
			else return middle;
		}
			return -1;	
	}
}