折半查找(二分查找)的递归和非递归算法

package com.my.test;/** * 折半查找(二分查找)的递归和非递归算法. 说明:  * 1、要求所查找的数组已有序,并且其中元素已实现Comparable<T>接口,如Integer、String等. * 2、非递归查找使用search();,递归查找使用searchRecursively(); **/public class BinarySearch<T extends Comparable<T>> {private T[] data;// 要排序的数据public BinarySearch(T[] data) {this.data = data;}public int search(T key) {int low;int high;int mid;if (data == null) {return -1;}low = 0;high = data.length - 1;while (low <= high) {mid = (low + high) / 2;//System.out.println("mid " + mid + " mid value:" + data[mid]);if (key.compareTo(data[mid]) < 0) {high = mid - 1;} else if (key.compareTo(data[mid]) > 0) {low = mid + 1;} else if (key.compareTo(data[mid]) == 0) {return mid;}}return -1;}private int doSearchRecursively(int low, int high, T key) {int mid;int result;if (low <= high) {mid = (low + high) / 2;result = key.compareTo(data[mid]);//System.out.println("mid " + mid + " mid value:" + data[mid]);if (result < 0) {return doSearchRecursively(low, mid - 1, key);} else if (result > 0) {return doSearchRecursively(mid + 1, high, key);} else if (result == 0) {return mid;}}return -1;}public int searchRecursively(T key) {if (data == null) {return -1;}return doSearchRecursively(0, data.length - 1, key);}public static void main(String[] args) {Integer[] data = { 1, 4, 5, 8, 15, 33, 48, 77, 96 };BinarySearch<Integer> binSearch = new BinarySearch<Integer>(data);System.out.println("Key index:" + binSearch.search(33));System.out.println("Key index:" + binSearch.searchRecursively(3));String[] dataStr = { "A", "C", "F", "J", "L", "N", "T" };BinarySearch<String> binSearch1 = new BinarySearch<String>(dataStr);System.out.println("Key index:" + binSearch1.search("T"));}}