题目如下: In a project, you have a list of required skills req_skills, and a list of people.  The i-th person people[i] contains a list of skills that person has. Consider a sufficient team: a set of people such that for every required skill in req_skill…

题目如下: Return the lexicographically smallest subsequence of text that contains all the distinct characters of text exactly once. Example 1: Input: "cdadabcc" Output: "adbc" Example 2: Input: "abcd" Output: "abcd" Exa…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/smallest-integer-divisible-by-k/ 题目描述 Given a positive integer K, you need find the smallest positive integer N such that N is divisible b…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 DFS BFS 日期 题目地址:https://leetcode.com/problems/smallest-string-starting-from-leaf/ 题目描述 Given the root of a binary tree, each node has a value from 0 to 25 representing the lett…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/smallest-range-ii/description/ 题目描述 Given an array A of integers, for each integer A[i] we need to choose either x = -K or x = K, and add…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 题目地址: https://leetcode.com/problems/smallest-range/description/ 题目描述: You have k lists of sorted integers in ascending order. Find the smallest range that includes at least one number from each…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 数学计算 日期 题目地址:https://leetcode.com/problems/smallest-range-i/description/ 题目描述 Given an array A of integers, for each integer A[i] we may choose any x with -K <= x <= K, and ad…

原题 An image is represented by a binary matrix with 0 as a white pixel and 1 as a black pixel. The black pixels are connected, i.e., there is only one black region. Pixels are connected horizontally and vertically. Given the location (x, y) of one of…

题目如下: You are given some lists of regions where the first region of each list includes all other regions in that list. Naturally, if a region X contains another region Y then X is bigger than Y. Given two regions region1, region2, find out the smalle…

题目如下: You are given a string s, and an array of pairs of indices in the string pairs where pairs[i] = [a, b] indicates 2 indices(0-indexed) of the string. You can swap the characters at any pair of indices in the given pairs any number of times. Retu…

题目如下: Given a positive integer K, you need find the smallest positive integer N such that N is divisible by K, and N only contains the digit 1. Return the length of N.  If there is no such N, return -1. Example 1: Input: 1 Output: 1 Explanation: The…

题目如下: Given the root of a binary tree, each node has a value from 0 to 25representing the letters 'a' to 'z': a value of 0 represents 'a', a value of 1 represents 'b', and so on. Find the lexicographically smallest string that starts at a leaf of thi…

作者: 负雪明烛 id: fuxuemingzhu 个人博客: http://fuxuemingzhu.cn/ 目录 题目描述 题目大意 解题方法 日期 题目地址:https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes/description/ 题目描述 Given a binary tree rooted at root, the depth of each node is the shortest d…

题目如下: 解题思路:简单的不能再简单的题目了,对于任意一个A[i]来说,其可能的最小的最大值是A[i]-K,最大的最小值是A[i]+K.遍历数组,求出所有元素中最大的最小值和最小的最大值,两者之差(小于零则取零)就是答案. 代码如下: class Solution(object): def smallestRangeI(self, A, K): """ :type A: List[int] :type K: int :rtype: int """…

题目如下: 解题思路:我的思路是先找出最大值.对于数组中任意一个元素A[i]来说,如果A[i] + K 是B中的最大值,那么意味着从A[i+1]开始的元素都要减去K,即如果有A[i] + K >= A[-1] - K,那么A[i] + K 就可以作为最大值而存在:如果A[i] + K是最大值,那么最大的最小值是多少呢?因为A[i] 左边的元素都比A[i]小,所以其左边的元素都可以加上K,最大的最小值就会在 A[0] + K 和 A[i+1] - K 之间产生.遍历数组,计算每一个A[i] + K…

题目如下: 解题思路:几乎和[leetcode]719. Find K-th Smallest Pair Distance 的方法一样.只不过一个是减法一个是乘法,还有一点区别是[leetcode]719. Find K-th Smallest Pair Distance中i-j和j-i只算一个元素,而本题中i*j与j*i算两个元素. 代码如下: class Solution(object): def findKthNumber(self, m, n, k): """ :ty…

[LeetCode]378. Kth Smallest Element in a Sorted Matrix 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/kth-smallest-element-in-a-sorted-matrix/description/ 题目描述: Given a n x n matrix where each of the rows and columns are sorted in ascen…

[LeetCode]373. Find K Pairs with Smallest Sums 解题报告(Python) 标签: LeetCode 题目地址:https://leetcode.com/problems/find-k-pairs-with-smallest-sums/description/ 题目描述: You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k…

链接:https://leetcode.com/tag/heap/ [23] Merge k Sorted Lists [215] Kth Largest Element in an Array (无序数组中最小/大的K个数)(2018年11月30日第一次复习) 给了一个无序数组,可能有重复数字,找到第 k 个最大的元素并且返回这个元素值. 题解:直接用直接用个堆保存数组中最大的 K 个数.时间复杂度是 O(NlogK). //时间复杂度是 O(NlogK), 用堆辅助. class Solut…

[94]Binary Tree Inorder Traversal [95]Unique Binary Search Trees II (2018年11月14日,算法群) 给了一个 n,返回结点是 1 - n 的所有形态的BST. 题解:枚举每个根节点 r, 然后递归的生成左右子树的所有集合,然后做笛卡尔积. /** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * Tr…

题目如下: We are given a linked list with head as the first node.  Let's number the nodes in the list: node_1, node_2, node_3, ... etc. Each node may have a next larger value: for node_i, next_larger(node_i) is the node_j.val such that j > i, node_j.val…

目录 二分查找 排序的写法 BFS的写法 DFS的写法 回溯法 树 递归 迭代 前序遍历 中序遍历 后序遍历 构建完全二叉树 并查集 前缀树 图遍历 Dijkstra算法 Floyd-Warshall算法 Bellman-Ford算法 最小生成树 Kruskal算法 Prim算法 拓扑排序 双指针 动态规划 状态搜索 贪心 本文的目的是收集一些典型的题目,记住其写法,理解其思想,即可做到一通百通.欢迎大家提出宝贵意见! 博主有算法题解的微信公众号啦,欢迎关注「负雪明烛」,持续更新算法题的解题思路…

[LeetCode]Longest Word in Dictionary through Deleting 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/longest-word-in-dictionary-through-deleting/#/description 题目描述: Given a string and a string dictionary, find the longest string in the di…

[LeetCode]697. Degree of an Array 解题报告 标签(空格分隔): LeetCode 题目地址:https://leetcode.com/problems/degree-of-an-array/description/ 题目描述: Given a non-empty array of non-negative integers nums, the degree of this array is defined as the maximum frequency of…

[LeetCode]743. Network Delay Time 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/network-delay-time/description/ 题目描述: There are N network nodes, labelled 1 to N. Given times…

[LeetCode]851. Loud and Rich 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/loud-and-rich/description/ 题目描述: In a group of N people (labelled 0, 1, 2, -, N-1), each person ha…

[LeetCode]556. Next Greater Element III 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/next-greater-element-iii/description/ 题目描述: Given a positive 32-bit integer n, you need…

[LeetCode]402. Remove K Digits 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/remove-k-digits/description/ 题目描述: Given a non-negative integer num represented as a string, rem…

[LeetCode]Minimum Depth of Binary Tree Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node. 递归和非递归,此提比较简单.广度优先遍历即可.关键之处就在于如何保持访问深度. 下面是4种代码: im…

Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3, Return [1,3,3,1]. Note: Could you optimize your algorithm to use only O(k) extra space? 思路:最简单的方法就是依照[Leetcode]Pascal's Triangle 的方式自顶向下依次求解,但会造成空间的浪费.若仅仅用一个vect…