Codeforces Global Round 23 D. Paths on the Tree

Codeforces Round 832 (Div. 2) D. Yet Another Problem

Codeforces Round 820 (Div. 3) F. Kirei and the Linear Function

2737. Find the Closest Marked Node

You are given a positive integer n which is the number of nodes of a 0-indexed directed weighted graph and a 0-indexed 2D array edges where edges[i] = [ui, vi, wi] indicates that there is an edge from node ui to node vi with weight wi.

You are also given a node s and a node array marked; your task is to find the minimum distance from s to any of the nodes in marked.

Return an integer denoting the minimum distance from s to any node in marked or -1 if there are no paths from s to any of the marked nodes.

2674. Split a Circular Linked List

Given a circular linked list list of positive integers, your task is to split it into 2 circular linked lists so that the first one contains the first half of the nodes in list (exactly ceil(list.length / 2) nodes) in the same order they appeared in list, and the second one contains the rest of the nodes in list in the same order they appeared in list.

Return an array answer of length 2 in which the first element is a circular linked list representing the first half and the second element is a circular linked list representing the second half.

A circular linked list is a normal linked list with the only difference being that the last node’s next node, is the first node.

2743. Count Substrings Without Repeating Character

You are given a string s consisting only of lowercase English letters. We call a substring special if it contains no character which has occurred at least twice (in other words, it does not contain a repeating character). Your task is to count the number of special substrings. For example, in the string "pop", the substring "po" is a special substring, however, "pop" is not special (since 'p' has occurred twice).

Return the number of special substrings.

A substring is a contiguous sequence of characters within a string. For example, "abc" is a substring of "abcd", but "acd" is not.

2753. Count Houses in a Circular Street II

You are given an object street of class Street``k which represents a maximum bound for the number of houses in that street (in other words, the number of houses is less than or equal to k). Houses’ doors could be open or closed initially (at least one is open).

Initially, you are standing in front of a door to a house on this street. Your task is to count the number of houses in the street.

The class Street contains the following functions which may help you:

• void closeDoor(): Close the door of the house you are in front of.
• boolean isDoorOpen(): Returns true if the door of the current house is open and false otherwise.
• void moveRight(): Move to the right house.

1 to n, then the right house of housei is housei+1 for i < n, and the right house of housen is house1.

Return ans which represents the number of houses on this street.

2714. Find Shortest Path with K Hops

You are given a positive integer n which is the number of nodes of a 0-indexed undirected weighted connected graph and a 0-indexed 2D array edges where edges[i] = [ui, vi, wi] indicates that there is an edge between nodes ui and vi with weight wi.

You are also given two nodes s and d, and a positive integer k, your task is to find the shortest path from s to d, but you can hop over at most k edges. In other words, make the weight of at most k edges 0 and then find the shortest path from s to d.

Return the length of the shortest path from s to d with the given condition.

2702. Minimum Operations to Make Numbers Non-positive

You are given a 0-indexed integer array nums and two integers x and y. In one operation, you must choose an index i such that 0 <= i < nums.length and perform the following:

• Decrement nums[i] by x.
• Decrement values by y at all indices except the ith one.

Return the minimum number of operations to make all the integers in nums less than or equal to zero.

Educational Codeforces Round 138 (Rated for Div. 2) D. Counting Arrays