java二分查找

算法书第一个程序，二分查找

代码如下

public class BinarySearchSecond {
	public static void main(String[] args) {
		 int[] a = {12,23,45,1,5,89,45,123,18};
		 Arrays.sort(a);
		 for(int b : a) {
			 System.out.print(b+",");
		 }
		 Boolean flag = BianrySearch(13,a);
		 System.out.println(flag);
	}

	private static Boolean BianrySearch(int i,int[] a) {
		 if(ia[a.length-1]) {
			 return false;
		 }else if(i==a[0] || i== a[a.length-1]) {
			 return true;
		 }else {
			 int head = 0;
			 int tail = a.length-1;
			 while(heada[mid]) {
					 head = mid+1;
				 }else if(i

想算法还是用笔，用一个例子在纸上写下来比较好。起码思路清晰