二分查找算法

1.二分查找算法分析

2.代码实现

package com.vince.bs;import java.util.Arrays;/** * 二分查找法 * @author lamp * */public class BinarySearchDemo {public static void main(String[] args) {int[] number = {4,58,11,34,88,45};//必须保正数列是有序的Arrays.sort(number);//排序int index = binarySearch(number,11);System.out.println(index);}//二分查找算法实现private static int binarySearch(int[] x,int n) {int start = 0;//起始位置int end = x.length-1;//结束位置int mid = -1;while(start<=end){mid = (start+end)/2;//求中间位置if(x[mid]==n){//表示要找的值已经找到return mid;}else if(x[mid]<n){start = mid+1;}else if(x[mid]>n){end = mid -1;}}return -1;}}