查找算法

线性查找

二分查找算法

package com.wei.search;

/**
 * @program: data_structure
 * @description: 二分查找
 * @author: wei
 * @create: 2021-07-17 21:03
 **/
public class BinarySearch {
    public static void main(String[] args) {
        int [] array = {1,2,3,4,5,6,7,8};
        int target = 500;
        int res = binarySearch(array,target,0,array.length-1);
        if(res==-1){
            System.out.printf("search %d fault!",target);
        }else{
            System.out.printf("目标值：%d的索引位置为"+res,target);
        }
    }

    public static int binarySearch(int[] array, int target, int left, int right) {
        if (left>right){
            return -1;
        }
        int pivot = (left + right) >> 1;
        if (target < array[pivot]) {
            return binarySearch(array, target, left, pivot - 1);
        } else if (target > array[pivot]) {
            return binarySearch(array, target,pivot + 1,right);
        }else{
            return pivot;
        }
    }
}