选择法排序数组+折半查找判断输入的数是否在数组中

package com.shu;
import java.util.*;

public class example2_5 {
	public static void main(String[] args) {
	int start=0,end,middle;
	int a[] = {23,120,34,3,78,90,12,236};
	int N = a.length;
	//选择法排序数组
	for(int i=0;i<N;i++){
		for(int j=i+1;j<N;j++){
			if(a[j]<a[i]){
				int t = a[j];
				a[j] = a[i];
				a[i] = t;
			}
		}
	}
	Scanner reader = new Scanner(System.in);
	System.out.println("输入整数，通过程序判断该整数是否在数组中");
	int number = reader.nextInt();
	int count = 0;
	end = N;
	middle = (start+end)/2;
	
	//折半查找
	while(number!=a[middle]){
		if(number>a[middle]){
			start = middle;
		}else if(number<a[middle]){
			end = middle;
		}
		middle = (start+end)/2;
		count++;
		if(count>N/2){break;}
		}
	if(count>N/2){
		System.out.printf("%d不在数组中",number);
	}else{
		System.out.printf("%d在数组中",number);
	}		
	}
}