package com.xiaojihua.datastructure;

public class BanarySearch {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Integer[] arr = {-3,-2,-2,-1,2,4,5,6};
		int index = binarySearch(arr,-1);
		System.out.println(index);
	}

	/**
	 * 折半查詢，通過泛型實現，接收所有實現comparable介面的型別
	 * @param a
	 * @param x
	 * @return
	 */
	public static <AnyType extends Comparable<? super AnyType>> int binarySearch(AnyType[] a,AnyType x){

		int low = 0, hight = a.length - 1;

		while(low <= hight){
			int mid = (low + hight)/2;
			if(a[mid].compareTo(x) < 0){
				low = mid + 1;
			}else if(a[mid].compareTo(x)>0){
				hight = mid - 1;
			}else{
				return mid;
			}

		}
		return -1;

	}

}