博客
关于我
LeetCode.581 Shortest Unsorted Continuous Subarray
阅读量:806 次
发布时间:2019-03-17

本文共 2372 字,大约阅读时间需要 7 分钟。

To solve this problem, we need to find the shortest continuous subarray such that sorting this subarray in ascending order would make the entire array sorted in ascending order as well.

Approach

The approach to solve this problem involves the following steps:

  • Sort the Array: First, we create a sorted version of the input array. This helps us identify the segments of the array that are out of order.

  • Identify Differences: We compare the original array with the sorted array to find the indices where they first differ (start of the unsorted segment) and where they last differ (end of the unsorted segment).

  • Determine the Subarray Length: The length of the shortest subarray that needs to be sorted is given by the range from the first differing index to the last differing index, inclusive.

  • Solution Code

    public class Solution {    public int findMinimumSubarrayLength(int[] nums) {        int n = nums.length;        int[] sorted = Arrays.copyOf(nums, n);        Arrays.sort(sorted);                int start = 0;        while (start < n && sorted[start] == nums[start]) {            start++;        }                if (start >= n) {            return 0;        }                int end = n - 1;        while (end >= 0 && sorted[end] == nums[end]) {            end--;        }                return end - start + 1;    }}

    Explanation

  • Sorting the Array: We create a sorted version of the input array to compare against the original array and identify the unsorted segments.

  • Finding the Start of the Subarray: By iterating through the original array, we find the first index where the value does not match the corresponding value in the sorted array. This index marks the beginning of the segment that needs to be sorted.

  • Finding the End of the Subarray: Similarly, by iterating from the end of the array, we find the last index where the value does not match the corresponding value in the sorted array. This index marks the end of the segment that needs to be sorted.

  • Calculating the Length: The length of the subarray is calculated as the difference between the end and start indices, plus one.

  • This approach ensures that we efficiently find the shortest subarray that, when sorted, will result in the entire array being sorted. The time complexity is dominated by the sorting step, making it (O(n \log n)), which is efficient for large arrays up to 10,000 elements.

    转载地址:http://ekjez.baihongyu.com/

    你可能感兴趣的文章
    php后台“爬虫”模拟登录第三方系统
    查看>>
    php后台的在控制器中就可以实现阅读数增加
    查看>>
    php命令行生成项目结构
    查看>>
    php命名空间
    查看>>
    PHP命名空间带来的干扰
    查看>>
    PHP和MySQL Web开发从新手到高手,第1天-搭建PHP开发环境
    查看>>
    php商店管理系统,基于PHP的商店管理系统.doc
    查看>>
    PHP四大主流框架的优缺点总结
    查看>>
    PHP图片处理—PNG透明缩放并生成灰图
    查看>>
    php在liunx系统中设置777权限不起作用解决方法
    查看>>
    PHP基于openssl实现的非对称加密操作
    查看>>
    php基本符号大全
    查看>>
    php基础篇-二维数组排序 array_multisort
    查看>>
    php基础配置环境变量
    查看>>
    php增删改查封装方法
    查看>>
    springboot之jar包Linux后台启动部署及滚动日志查看且日志输出至文件保存(超级详细)
    查看>>
    php多条件筛选功能的实现
    查看>>
    php多线程
    查看>>
    PHP大数组循环-避免产生Notice或者是Warning
    查看>>
    PHP大数组过滤元素、修改元素性能分析
    查看>>