Leetcode 797: All Paths From Source to Target

Given a directed acyclic graph (DAG) of n nodes labeled from 0 to n - 1, find all possible paths from node 0 to node n - 1 and return them in any order. The graph is given as follows: graph[i] is a list of all nodes you can visit from node i (i.e., there is a directed edge from node i to node graph[i][j]). https://leetcode.com/problems/all-paths-from-source-to-target/description/ class Solution { public List<List<Integer>> allPathsSourceTarget(int[][] ...

Leetcode 1167: Minimum Cost to Connect Sticks

You have some number of sticks with positive integer lengths. These lengths are given as an array sticks, where sticks[i] is the length of the ith stick. You can connect any two sticks of lengths x and y into one stick by paying a cost of x + y. You must connect all the sticks until there is only one stick remaining. Return the minimum cost of connecting ...

Leetcode 1834: Single-Threaded CPU

You are given n​​​​​​ tasks labeled from 0 to n - 1 represented by a 2D integer array tasks, where tasks[i] = [enqueueTimei, processingTimei] means that the i​​​​​​th​​​​ task will be available to process at enqueueTimei and will take processingTimeito finish processing. You have a single-threaded CPU that can process at most one task at a time and will act in the following way: If the CPU is idle ...

Linked List Components

Title: Linked List Components Source: leetcode.com We are given head, the head node of a linked list containing unique integer values. We are also given the list G, a subset of the values in the linked list. Return the number of connected components in G, where two values are connected if they appear consecutively in ...

Increasing Order Search Tree

Title: Increasing Order Search Tree Source: leetcode.com Given a tree, rearrange the tree in in-order so that the leftmost node in the tree is now the root of the tree, and every node has no left child and only 1 right child (Increasing order search tree). Example 1: Input: [5,3,6,2,4,null,8,1,null,null,null,7,9] 5 / \ 3 6 ...

Find all Anagrams in a String 2

Title: Custom Sort String Source: leetcode.com Given a string s and a non-empty string p, find all the start indices of p‘s anagrams in s. Strings consists of lowercase English letters only and the length of both strings s and p will not be larger than 20,100. The order of output does not matter. Example ...

Custom Sort String

Title: Custom Sort String Source: leetcode.com S and T are strings composed of lowercase letters. In S, no letter occurs more than once. S was sorted in some custom order previously. We want to permute the characters of T so that they match the order that S was sorted. More specifically, if x occurs before ...

Monotonic Array

Title: Monotonic Array Source: leetcode.com An array is monotonic if it is either monotone increasing or monotone decreasing. An array A is monotone increasing if for all i <= j, A[i] <= A[j]. An array A is monotone decreasing if for all i <= j, A[i] >= A[j]. Return true if and only if the ...

Binary Watch Problem

Title: Binary Watch Source: leetcode.com A binary watch has 4 LEDs on the top which represent the hours (0-11), and the 6 LEDs on the bottom represent the minutes (0-59). Each LED represents a zero or one, with the least significant bit on the right. For example, the above binary watch reads “3:25”. Given a ...

Leaf-Similar trees

Title: Leaf-Similar TreesSource: leetcode.com Consider all the leaves of a binary tree. From left to right order, the values of those leaves form a leaf value sequence. For example, in the given tree above, the leaf value sequence is (6, 7, 4, 9, 8). Two binary trees are considered leaf-similar if their leaf value sequence ...