1359. Count All Valid Pickup and Delivery Options
Given n orders, each order consist in pickup and delivery services.
Count all valid pickup/delivery possible sequences such that delivery(i) is always after of pickup(i).
Since the answer may be too large, return it modulo 10^9 + 7.
2190. Most Frequent Number Following Key In an Array
You are given a 0-indexed integer array nums. You are also given an integer key, which is present in nums.
For every unique integer target in nums, count the number of times target immediately follows an occurrence of key in nums. In other words, count the number of indices i such that:
- 0 <= i <= n - 2,
- nums[i] == key and,
- nums[i + 1] == target.
Return the target with the maximum count. The test cases will be generated such that the target with maximum count is unique.
2191. Sort the Jumbled Numbers
You are given a 0-indexed integer array mapping which represents the mapping rule of a shuffled decimal system. mapping[i] = j means digit i should be mapped to digit j in this system.
The mapped value of an integer is the new integer obtained by replacing each occurrence of digit i in the integer with mapping[i] for all 0 <= i <= 9.
You are also given another integer array nums. Return the array nums sorted in non-decreasing order based on the mapped values of its elements.
Notes:
- Elements with the same mapped values should appear in the same relative order as in the input.
- The elements of nums should only be sorted based on their mapped values and not be replaced by them.
2193. Minimum Number of Moves to Make Palindrome
You are given a string s consisting only of lowercase English letters.
In one move, you can select any two adjacent characters of s and swap them.
Return the minimum number of moves needed to make s a palindrome.
Note that the input will be generated such that s can always be converted to a palindrome.
2192. All Ancestors of a Node in a Directed Acyclic Graph
You are given a positive integer n representing the number of nodes of a Directed Acyclic Graph (DAG). The nodes are numbered from 0 to n - 1 (inclusive).
You are also given a 2D integer array edges, where edges[i] = [fromi, toi] denotes that there is a unidirectional edge from fromi to toi in the graph.
Return a list answer, where answer[i] is the list of ancestors of the ith node, sorted in ascending order.
A node u is an ancestor of another node v if u can reach v via a set of edges.
1192. Critical Connections in a Network
There are n servers numbered from 0 to n - 1 connected by undirected server-to-server connections forming a network where connections[i] = [ai, bi] represents a connection between servers ai and bi. Any server can reach other servers directly or indirectly through the network.
A critical connection is a connection that, if removed, will make some servers unable to reach some other server.
Return all critical connections in the network in any order.
352. Data Stream as Disjoint Intervals
Given a data stream input of non-negative integers a1, a2, …, an, summarize the numbers seen so far as a list of disjoint intervals.
Implement the SummaryRanges class:
- SummaryRanges() Initializes the object with an empty stream.
- void addNum(int val) Adds the integer val to the stream.
- int[][] getIntervals() Returns a summary of the integers in the stream currently as a list of disjoint intervals [starti, endi].
1319. Number of Operations to Make Network Connected
There are n computers numbered from 0 to n - 1 connected by ethernet cables connections forming a network where connections[i] = [ai, bi] represents a connection between computers ai and bi. Any computer can reach any other computer directly or indirectly through the network.
You are given an initial computer network connections. You can extract certain cables between two directly connected computers, and place them between any pair of disconnected computers to make them directly connected.
Return the minimum number of times you need to do this in order to make all the computers connected. If it is not possible, return -1.