java算法之二分查找法的实例详解

package me.geed.algorithms;  public class BinarySearch {    /**    * 从一个有序数组(如升序)中找到值为key元素    * @param key    * @param array    * @return 如果找到目标元素，则返回其在数组中的索引，否则返回-1    */   public static int find(int key, int[] array){     int low = 0;     int high = array.length - 1;     while (low <= high) {       int mid = low + (high - low) / 2;       if (array[mid] > key) {         high = mid - 1;       } else if (array[mid] < key) {         low = mid + 1;       } else {         return mid;       }           }     return -1;      }      public static void main(String[] args) {     // TODO Auto-generated method stub     int[] array = {2, 3, 5, 9, 10, 13, 23, 45, 78, 89, 100, 128, 256};     System.out.println("目标元素索引值：" + BinarySearch.find(9, array));         System.out.println("目标元素索引值：" + BinarySearch.find(26, array));   }  } 

目标元素索引值：3 目标元素索引值：-1