［抄题］: Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer. Example 1: I…

整体上3个题都是求subarray,都是同一个思想,通过累加,然后判断和目标k值之间的关系,然后查看之前子数组的累加和. map的存储:560题是存储的当前的累加和与个数 561题是存储的当前累加和的余数与第一次出现这个余数的位置 325题存储的是当前累加和与第一次出现这个和的位置 其实561与325都是求的最长长度,那就一定要存储的是第一次出现满足要求的位置,中间可能还出现这种满足要求的情况,但都不能进行存储 560. Subarray Sum Equals K 求和为k的连续子数组的个数 h…

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer. Example 1: Input:…

非负数组中找到和为K的倍数的连续子数组 详见:https://leetcode.com/problems/continuous-subarray-sum/description/ Java实现: 方法一: class Solution { public boolean checkSubarraySum(int[] nums, int k) { for(int i=0;i<nums.length;++i){ int sum=nums[i]; for(int j=i+1;j<nums.length…

class Solution { public: bool checkSubarraySum(vector<int>& nums, int k) { unordered_map<int,int> allsum; allsum.insert(make_pair(,-)); ; ;i<nums.size();++i) { sum+=nums[i]; if(k)sum%=k; auto j=allsum.find(sum); if(j!=allsum.end()) { )r…

题目如下: 解题思路:本题需要用到这么一个数学定理.对于任意三个整数a,b,k(k !=0),如果 a%k = b%k,那么(a-b)%k = 0.利用这个定理,我们可以对数组从头开始进行求和,同时利用字典保存余数(key:余数,value:最早出现这个余数的元素下标),每累加一个元素都对k取余数,如果余数在字典中存在并且两个元素之间的下标差大于等于2,即表示存在这样的subarray.而对于k=0的情况,必须要出现至少两个出现至少连续两个0才能符合条件:当然,因为0*k = 0,所以如果数组中…

Given an integer array, find a continuous rotate subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are duplicate answer, return anyone. The answer can b…

LintCode 402: Continuous Subarray Sum 题目描述 给定一个整数数组,请找出一个连续子数组,使得该子数组的和最大.输出答案时,请分别返回第一个数字和最后一个数字的下标.(如果两个相同的答案,请返回其中任意一个) 样例 给定[-3, 1, 3, -3, 4], 返回[1,4]. Thu Feb 23 2017 思路 本题有很多解法,最巧妙的解法就是一遍扫描记忆的方法了,时间复杂度为\(O(n)\). 用一个变量记录连续累加的和,当和为负数时,变量清零,从下一个数字…

Continuous Subarray Sum II   Given an circular integer array (the next element of the last element is the first element), find a continuous subarray in it, where the sum of numbers is the biggest. Your code should return the index of the first number…

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer. Example 1: Input:…

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer. Example 1: Input:…

Given an integer array, find a continuous subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are duplicate answer, return anyone) Have you met this quest…

Given an integer array, find a continuous subarray where the sum of numbers is the biggest. Your code should return the index of the first number and the index of the last number. (If their are duplicate answer, return anyone) Example Give A = [-3, 1…

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too. You need to find the shortest such subarray and output its length. E…

Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multiple of k, that is, sums up to n*k where n is also an integer. Example 1: Input:…

原题链接在这里:https://leetcode.com/problems/continuous-subarray-sum/description/ 题目: Given a list of non-negative numbers and a target integer k, write a function to check if the array has a continuous subarray of size at least 2 that sums up to the multip…

Description Given an circular integer array (the next element of the last element is the first element), find a continuous subarray in it, where the sum of numbers is the biggest. Your code should return the index of the first number and the index of…

题目 连续子数组求和 给定一个整数数组,请找出一个连续子数组,使得该子数组的和最大.输出答案时,请分别返回第一个数字和最后一个数字的值.(如果两个相同的答案,请返回其中任意一个) 样例 给定 [-3, 1, 3, -3, 4], 返回[1,4]. 解题 法一:直接暴力,时间复杂度O(N2),时间超时 public class Solution { /** * @param A an integer array * @return A list of integers includes the i…

2018-10-03 01:12:42 问题描述: 问题求解: 本题本质上其实是一个preSum问题的变种,每次求preSum % k,并将之保存到map中,如果之后再次得到相同的余数,则表示这两者之间的和是k的整数倍. 需要注意的有两点: 1)map初始化的时候需要加入(0, -1) 2)如果k == 0,那么直接将sum加入到map中即可 public boolean checkSubarraySum(int[] nums, int k) { if (nums.length == 0) re…

文章目录 题意 思路 特殊情况k=0 Source Code 1 Source Code 2 题意 给定一个数组和一个整数k,返回是否存在一个长度至少为2的连续子数组的和为k的倍数. 思路 和上一篇博客的思路基本一致. LeetCode subarray-sum-equals-k题解 所不同的是,子数组至少长度为2.因此需要一个缓冲区,延缓往Hash表中加数的操作. 另外,因为是和变成是k的倍数.利用同余的知识易得我们维护的前缀和是群ZkZ_kZk​中的和. ps.这里我犯了一个错误,没有考虑k…

A variation to a classical DP: LCS. class Solution { public: /** * @param A an integer array * @return A list of integers includes the index of * the first number and the index of the last number */ vector<int> continuousSubarraySum(vector<int>…

思路: 令sum[p]表示p位置的前缀和.如果sum[i] % k == sum[j] % k (j - i > 1),则存在子段(i, j]的和能够整除k. 实现: class Solution { public: bool checkSubarraySum(vector<int>& nums, int k) { ) return false; int n = nums.size(); ; i < n - ; i++) && nums[i + ] == )…

1.题目描述 2.循环计算即可 3.代码 bool checkSubarraySum(vector<int>& nums, int k) { ){ return false ; } ; i < nums.size() ; ++i){ int sum_i = nums[i]; ; j < nums.size(); ++j){ sum_i += nums[j]; && k == ) return false; && k == ) return t…

2sum 如果数组是无序的,先排序(n*logn),然后用两个指针i,j,各自指向数组的首尾两端,令i=0,j=n-1,然后i++,j--,逐次判断a[i]+a[j]?=sum,如果某一刻a[i]+a[j]>sum,则要想办法让sum 的值减小,所以此刻i 不动,j--,如果某一刻a[i]+a[j]<sum,则要想办法让sum 的值增大,所以此刻i++,j 不动.所以,数组无序的时候,时间复杂度最终为O(n*logn+n)=O(n*logn),若原数组是有序的,则不需要事先的排序,直接O(n)…

Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Input:nums = [1,1,1], k = 2 Output: 2 Note: The length of the array is in range [1, 20,000]. The range of numbers…

Given an array of integers and an integer k, you need to find the total number of continuous subarrays whose sum equals to k. Example 1: Input:nums = [1,1,1], k = 2 Output: 2 Note: The length of the array is in range [1, 20,000]. The range of numbers…

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too. You need to find the shortest such subarray and output its length. E…

Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be sorted in ascending order, too. You need to find the shortest such subarray and output its length. E…

581. 最短无序连续子数组 581. Shortest Unsorted Continuous Subarray 题目描述 给定一个整型数组,你需要寻找一个连续的子数组,如果对这个子数组进行升序排序,那么整个数组都会变为升序排序. 你找到的子数组应是最短的,请输出它的长度. LeetCode581. Shortest Unsorted Continuous Subarray 示例 1: 输入: [2, 6, 4, 8, 10, 9, 15] 输出: 5 解释: 你只需要对 [6, 4, 8,…

问题 给定一个整数数组,你需要寻找一个连续的子数组,如果对这个子数组进行升序排序,那么整个数组都会变为升序排序. 你找到的子数组应是最短的,请输出它的长度. 输入: [2, 6, 4, 8, 10, 9, 15] 输出: 5 解释: 你只需要对 [6, 4, 8, 10, 9] 进行升序排序,那么整个表都会变为升序排序. 说明 : 输入的数组长度范围在 [1, 10,000]. 输入的数组可能包含重复元素 ,所以升序的意思是<=. Given an integer array, you need…