java--chapter02--判断数是否在数组中

最新推荐文章于 2022-12-04 21:58:35 发布

huying1144

最新推荐文章于 2022-12-04 21:58:35 发布

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分类专栏： java

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public class Example2_5 {
	public static void main(String[] args){
		Sort a=new Sort();
		int [] a1={12,45,67,89,123,-45,67};
		a.sort(a1);
		a.find(a1);
			}	
}

import java.util.Scanner;
public class Sort {
	void sort(int[] a){
	int N=a.length;
	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;
			}
		}
	}
}
	void find(int[] a){
		int start = 0,end,middle;
		int N=a.length;
		Scanner scanner = new Scanner(System.in);
		System.out.println("输入整数，程序判断该证书是否在数组中：");
		int number =scanner.nextInt();
		int count = 0;
		end = N;
		middle=(start+end)/2;
		while(number!=a[middle]){
			if(number>a[number])
				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.\n",number);
		else
			System.out.printf("%d在数组中.\n",number);
	}
}

运行结果：