package tree.binarytree;
/**
* Created by Lanxiaowei
* Craated on 2016/12/12 13:51
* 判断给定的一个数字x是否在指定的一个有序的数字序列中存在
* 采用递归方式实现
*/
public class Test3 {
public static void main(String[] args) {
int x = 16;
int[] array = {1,2,3,4,5,6,7,8,9,10};
boolean exists = search(x,0,array.length - 1,array);
System.out.println(exists);
}
public static boolean search(int x,int from, int to,int[] array) {
if(null == array || array.length == 0) {
return false;
}
if(from > to) {
return false;
}
int mid = (from + to) / 2;
//如果刚好中间那个元素就是数字x
if(array[mid] == x) {
return true;
}
if(array[mid] > x) {
return search(x,from,mid - 1,array);
}
return search(x,mid + 1,to,array);
}
}