二分查找算法

 1 /*
 2  * 二分查找算法
 3  */
 4 public class BinarySerach {
 5     public static int binarySearch(int[] list, int key) {
 6         int low = 0;
 7         int high = list.length - 1;
 8         while (high >= low) {
 9             int mid = (low + high) / 2;
10             if (key == list[mid])
11                 return mid;
12             else if (key < list[mid])
13                 high = mid - 1;
14             else
15                 low = mid + 1;
16         }
17         return -low - 1;
18     }
19 
20     public static void main(String[] args) {
21         int[] list = { 2, 4, 7, 10, 11, 45, 50, 59, 60, 66, 69, 70 };
22         int lb = binarySearch(list, 10);
23         System.out.println("查找的值是: " + list[lb] + " 位置在第" + lb + "位");
24     }
25 }