二分查找，迭代和递归，java实现

直接上代码，递归式

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package cn.edu.cqupt.serach;public class HarfSearch {public static int search(int[] array,int start,int end,int target){int middle = (start+end)/2;if(target==array[middle])return middle;/* * 当数列只剩两个元素时{start,end} * 由于middle每次都等于start，故做特殊判断 *  */if(end==start+1)if(target==array[end])return end;elsereturn -1;if(target<array[middle])return search(array,start,middle,target);if(target>array[middle])return search(array,middle,end,target);return -1;}public static void main(String args[]){int array[]={1,100};int result= search(array,0,array.length-1,1);System.out.println(result);}}

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迭代式

package cn.edu.cqupt.serach;public class Search {public static  int halfSearch(int[]array,int target){int start= 0;int end =array.length-1;while(end>start+1){int middle=(start+end)/2;if(target==array[middle])return middle;if(target<array[middle])end=middle;elsestart=middle;}if(target==array[end])return end;if(target==array[start])return start;return -1;}public static void main(String args[]){int array[]={1,6,8,9,33,45,98,100};int result = halfSearch(array,1);System.out.println(result);}}

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