import java.util.Scanner;

public class BinarySearch {

/*
* 二分查找法
*/
public static int binarySearch(int[] a, int x, int n) {
int left = 0;
int right = n - 1;
while (left <= right) {
int middle = (left + right) / 2;
if (x == a[middle])
return middle;
if (x > a[middle])
left = middle + 1;
else
right = middle - 1;
}
return -1;
}

public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
// 输入数组个数
System.out.println("请输入数组元素的个数：");

int idex = sc.nextInt();
// 生成数组
int[] b = new int[idex];
// 输入元素
System.out.println("请输入元素：");
for (int i = 0; i < b.length; i++) {
b[i] = sc.nextInt();
}
System.out.println("输入的数组内容为：");
for (int a : b) {
System.out.println(a);
}
System.out.println("---------------------------");
// 排序
System.out.println("数组进行排序后输出为：");
b = sort(b);
for (int a : b) {
System.out.println(a);
}
System.out.println("---------------------------");
// 输入要查询的元素
System.out.println("请输入要查询的元素：");
int element = sc.nextInt();
int i = binarySearch(b, element, b.length);
     System.out.println(i);

}
// 由小到大排序（进行冒泡排序）
public static int[] sort(int[] a) {
for (int i = 0; i < a.length; i++) {
for (int j = 0; j < a.length - 1; j++) {
if (a[j] > a[j + 1]) {
int temp = a[j];
a[j] = a[j + 1];
a[j + 1] = temp;
}
}
}
return a;
}
}