Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A. Since the answer may be large, return the answer modulo 10^9 + 7. Example 1: Input: [3,1,2,4] Output: 17 Explanation: Subarrays are [3], [1],…

Given a circular array C of integers represented by A, find the maximum possible sum of a non-empty subarray of C. Here, a circular array means the end of the array connects to the beginning of the array.  (Formally, C[i] = A[i] when 0 <= i < A.leng…

Given an array consisting of n integers, find the contiguous subarray whose length is greater than or equal to k that has the maximum average value. And you need to output the maximum average value. Example 1: Input: [1,12,-5,-6,50,3], k = 4 Output:…

题目如下: 解题思路:我的想法对于数组中任意一个元素,找出其左右两边最近的小于自己的元素.例如[1,3,2,4,5,1],元素2左边比自己小的元素是1,那么大于自己的区间就是[3],右边的区间就是[4,5].那么对于元素2来说,和左边区间合并组成[2,3]以及和右边区间合并组成[2,4,5],这两段区间包括2在内的所有subarray的最小值都是2,其分别可以组成的subarry的个数是 len([3])和len([4,5]),左右区间合并在一起可以组成的subarray的个数是len([3])…

Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A. Since the answer may be large, return the answer modulo 10^9 + 7. Example 1: Input: [3,1,2,4] Output: 17 Explanation: Subarrays are [3], [1],…

Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. 典型的DP问题,递推条件还是想了有点长时间,代码如下所示: cl…

一.题目大意 https://leetcode.cn/problems/maximum-average-subarray-i/ 给你一个由 n 个元素组成的整数数组 nums 和一个整数 k . 请你找出平均数最大且 长度为 k 的连续子数组,并输出该最大平均数. 任何误差小于10^(-5)的答案都将被视为正确答案. 示例 1: 输入:nums = [1,12,-5,-6,50,3], k = 4 输出:12.75 解释:最大平均数 (12-5-6+50)/4 = 51/4 = 12.75 示例…

Given an array of integers A, find the sum of min(B), where B ranges over every (contiguous) subarray of A. Since the answer may be large, return the answer modulo 10^9 + 7. Example 1: Input: [3,1,2,4] Output: 17 Explanation: Subarrays are [3], [1],…

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 consisting of n integers, find the contiguous subarray whose length is greater than or equal to k that has the maximum average value. And you need to output the maximum average value. Example 1: Input: [1,12,-5,-6,50,3], k = 4 Output:…

Given an array consisting of n integers, find the contiguous subarray of given length k that has the maximum average value. And you need to output the maximum average value. Example 1: Input: [1,12,-5,-6,50,3], k = 4 Output: 12.75 Explanation: Maximu…

Level:   Medium 题目描述: 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]…

Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] has the largest sum = 6. More practice: If you have figur…

We have an array A of non-negative integers. For every (contiguous) subarray B = [A[i], A[i+1], ..., A[j]] (with i <= j), we take the bitwise OR of all the elements in B, obtaining a result A[i] | A[i+1] | ... | A[j]. Return the number of possible re…

题目 给定一个整数数组和一个整数 k,你需要找到该数组中和为 k 的连续的子数组的个数. 示例 1 : 输入:nums = [1,1,1], k = 2 输出: 2 , [1,1] 与 [1,1] 为两种不同的情况. 说明 : 数组的长度为 [1, 20,000]. 数组中元素的范围是 [-1000, 1000] ,且整数 k 的范围是 [-1e7, 1e7]. 来源:力扣(LeetCode) 链接:https://leetcode-cn.com/problems/subarray-sum-eq…

689. 三个无重叠子数组的最大和 给定数组 nums 由正整数组成,找到三个互不重叠的子数组的最大和. 每个子数组的长度为k,我们要使这3*k个项的和最大化. 返回每个区间起始索引的列表(索引从 0 开始).如果有多个结果,返回字典序最小的一个. 示例: 输入: [1,2,1,2,6,7,5,1], 2 输出: [0, 3, 5] 解释: 子数组 [1, 2], [2, 6], [7, 5] 对应的起始索引为 [0, 3, 5]. 我们也可以取 [2, 1], 但是结果 [1, 3, 5] 在…

560. 和为K的子数组 给定一个整数数组和一个整数 k,你需要找到该数组中和为 k 的连续的子数组的个数. 示例 1 : 输入:nums = [1,1,1], k = 2 输出: 2 , [1,1] 与 [1,1] 为两种不同的情况. 说明 : 数组的长度为 [1, 20,000]. 数组中元素的范围是 [-1000, 1000] ,且整数 k 的范围是 [-1e7, 1e7]. PS: 先附上简单一些的 class Solution { public int subarraySum(int[…

713. 乘积小于K的子数组 给定一个正整数数组 nums. 找出该数组内乘积小于 k 的连续的子数组的个数. 示例 1: 输入: nums = [10,5,2,6], k = 100 输出: 8 解释: 8个乘积小于100的子数组分别为: [10], [5], [2], [6], [10,5], [5,2], [2,6], [5,2,6]. 需要注意的是 [10,5,2] 并不是乘积小于100的子数组. 说明: 0 < nums.length <= 50000 0 < nums[i]…

2018-09-27 23:33:49 问题描述: 问题求解: 方法一.DP(MLE) 动态规划的想法应该是比较容易想到的解法了,因为非常的直观,但是本题的数据规模还是比较大的,如果直接使用动态规划,即使不MLE,也是肯定会在大规模的数据量上TLE的. public int sumSubarrayMins(int[] A) { int res = 0; int mod = (int)Math.pow(10, 9) + 7; int[][] dp = new int[A.length][A.len…

Find the contiguous subarray within an array (containing at least one number) which has the largest product. For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest product = 6. 很显然是一个动态规划的问题,找到递归表达式就可以了,考虑到会有负负相乘的问题,所以应…

给定 n 个整数,找出平均数最大且长度为 k 的连续子数组,并输出该最大平均数. 示例 1: 输入: [1,12,-5,-6,50,3], k = 4 输出: 12.75 解释: 最大平均数 (12-5-6+50)/4 = 51/4 = 12.75 注意: 1 <= k <= n <= 30,000. 所给数据范围 [-10,000,10,000]. class Solution { public: double findMaxAverage(vector<int>&…

思路: 对于每个数字A[i],使用单调栈找到A[i]作为最小值的所有区间数量,相乘并累加结果.时间复杂度O(n). 实现: class Solution { public: int sumSubarrayMins(vector<int>& A) { ; stack<int> st; int n = A.size(); ; ; i < n; i++) { while (!st.empty() && A[i] < A[st.top()]) { int…

Design and implement a TwoSum class. It should support the following operations:add and find. add - Add the number to an internal data structure.find - Find if there exists any pair of numbers which sum is equal to the value. For example,add(1); add(…

Find the sum of all left leaves in a given binary tree. Example: 3 / \ 9 20 / \ 15 7 There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24. 题目标签:Tree 这道题目给了我们一个二叉树,让我们找到所有左子叶之和.这里需要另外一个function - sumLeftLeaves 还要一…

Calculate the sum of two integers a and b, but you are not allowed to use the operator + and -. Example:Given a = 1 and b = 2, return 3. 题目标签:Bit Manipulation 这道题目让我们做两数之和,当然包括负数,而且不能用+,-等符号.所以明显是让我们从计算机的原理出发,运用OR,AND,XOR等运算法则.一开始自己想的如果两个数都是正数,那么很简单,…

An undirected, connected tree with N nodes labelled 0...N-1 and N-1 edges are given. The ith edge connects nodes edges[i][0] and edges[i][1] together. Return a list ans, where ans[i] is the sum of the distances between node i and all other nodes. Exa…

1. 题目 1.1 英文题目 Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum. 1.2 中文题目 给定一个整数数组 nums ,找到一个具有最大和的连续子数组(子数组最少包含一个元素),返回其最大和. 1.3输入输出 输入 输出 nums = [-2,1,-3,4,-1,2,…

题目描述 HZ偶尔会拿些专业问题来忽悠那些非计算机专业的同学.今天测试组开完会后,他又发话了:在古老的一维模式识别中,常常需要计算连续子向量的最大和,当向量全为正数的时候,问题很好解决.但是,如果向量中包含负数,是否应该包含某个负数,并期望旁边的正数会弥补它呢?例如:{6,-3,-2,7,-15,1,2,2},连续子向量的最大和为8(从第0个开始,到第3个为止).给一个数组,返回它的最大连续子序列的和,你会不会被他忽悠住?(子向量的长度至少是1) 方法一:穷举法 我们很自然地能想到穷举的办法,穷…

类似于背包问题,前提条件是数组全是正整数和0,先求和Sum,再从子数组中找出接近Sum/2的子数组 @interface TempState : NSObject @property (nonatomic,assign) int iIdx; @property (nonatomic,assign) int jIdx; @end @implementation TempState @end - (void)getSubArryMinABS{ // 输入 NSMutableArray *inputA…

Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn't one, return 0 instead. For example, given the array [2,3,1,2,4,3] and s = 7,the subarray [4,3] has the minimal…