二分搜索的题目

##二分搜索
针对有序的数组,主要是一些边界的问题
##leetcode_35
这里写图片描述

##题解

public class Leetcode_35 {
    public int searchInsert(int[] nums, int target) {
        int l = 0;
        int r = nums.length-1;

        while(l<=r)
        {
            int mid = (r+l)/2;
            if(target==nums[mid])
                return mid;

            else if(target>nums[mid])
                l = mid+1;
            else
                r = mid-1;
        }

        return l;

    }

    public static void main(String[] args)
    {
        int[] nums ={1,3,5,6};

        Leetcode_35 test = new Leetcode_35();
        int a = test.searchInsert(nums,7);
        System.out.println(a);
    }
}

##剑指offer_11
这里写图片描述

import java.util.ArrayList;
public class Solution {
    public int minNumberInRotateArray(int [] array) {
        int l = 0;
        int r = array.length-1;

        while(l<r)
        {
            int m = (l+r)/2;
            if(array[m]<=array[r])
                r = m;
            else
                l = m+1;
        }     
       return array[l];   
    }
}

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转载自blog.csdn.net/Ding_xiaofei/article/details/82745315
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