[LeetCode] Sort the Jumbled Numbers

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.
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[LeetCode] Minimum Number of Moves to Make Palindrome

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.

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[LeetCode] All Ancestors of a Node in a Directed Acyclic Graph

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.

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13th Place on LeetCode Weekly Contest

후기

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[Algorithm] LCA

Lowest Common Ancestor

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[LeetCode] Critical Connections in a Network

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.

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[LeetCode] Data Stream as Disjoint Intervals

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].
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[LeetCode] Number of Operations to Make Network Connected

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.

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[LeetCode] Champagne Tower

799. Champagne Tower

We stack glasses in a pyramid, where the first row has 1 glass, the second row has 2 glasses, and so on until the 100th row. Each glass holds one cup of champagne.

Then, some champagne is poured into the first glass at the top. When the topmost glass is full, any excess liquid poured will fall equally to the glass immediately to the left and right of it. When those glasses become full, any excess champagne will fall equally to the left and right of those glasses, and so on. (A glass at the bottom row has its excess champagne fall on the floor.)

For example, after one cup of champagne is poured, the top most glass is full. After two cups of champagne are poured, the two glasses on the second row are half full. After three cups of champagne are poured, those two cups become full - there are 3 full glasses total now. After four cups of champagne are poured, the third row has the middle glass half full, and the two outside glasses are a quarter full, as pictured below.

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[LeetCode] Goal Parser Interpretation

1678. Goal Parser Interpretation

You own a Goal Parser that can interpret a string command. The command consists of an alphabet of “G”, “()” and/or “(al)” in some order. The Goal Parser will interpret “G” as the string “G”, “()” as the string “o”, and “(al)” as the string “al”. The interpreted strings are then concatenated in the original order.

Given the string command, return the Goal Parser’s interpretation of command.

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