题目如下: 解题思路:题目定义的子序列宽度是最大值和最小值的差,因此可以忽略中间值.首先对数组排序,对于数组中任意一个元素,都可以成为子序列中的最大值和最小值而存在.例如数组[1,2,3,4,5,6],对于元素3来说,由左边[1,2]组成的所有子序列都可以以3为最大值的,而右边[4,5,6]组成的所有子序列都可以以3为最小值.根据排列组合的原理:[1,2]可以组成的子序列个数为C(2,1) + C(2,2) ,而[4,5,6]可以组成的子序列个数为C(3,1) + C(3,2) + C(3,3)…

[LeetCode]129. Sum Root to Leaf Numbers 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/sum-root-to-leaf-numbers/description/ 题目描述: Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a numbe…

[LeetCode]522. Longest Uncommon Subsequence II 解题报告(Python) 标签(空格分隔): LeetCode 作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址:https://leetcode.com/problems/longest-uncommon-subsequence-ii/description/ 题目描述: Given a list of strings, you…

[LeetCode]334. Increasing Triplet Subsequence 解题报告(Python) 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/increasing-triplet-subsequence/description/ 题目描述: Given an unsorted array return whether an increasing subsequence of length 3 exists or…

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, consider all non-empty subsequences of A. For any sequence S, let the width of S be the difference between the maximum and minimum element of S. Return the sum of the widths of all subsequences of A.  As the answer may b…

Difficulty: Easy  More:[目录]LeetCode Java实现 Description https://leetcode.com/problems/sum-of-square-numbers/submissions/ Given a non-negative integer c, your task is to decide whether there're two integers aand b such that a2 + b2 = c. Example 1: Inpu…

404. Sum of Left Leaves [题目]中文版  英文版 /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode(int x) : val(x), left(NULL), right(NULL) {} * }; */ class Solution { public: int sumOfLeftLea…

[Description] Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function twoSum should return indices of the two numbers such that they add up to the target,…

Given an array of integers A, consider all non-empty subsequences of A. For any sequence S, let the width of S be the difference between the maximum and minimum element of S. Return the sum of the widths of all subsequences of A. As the answer may be…