Shortest Path to Collect All Coins in a Tree

Problem Statement

Shortest Path to Collect All Coins in a Tree Problem Alex is playing a game in Hackerland. The city is a tree with tree_nodes vertices labeled 0 to tree_nodes - 1 . An array coins of size tree_nodes tells which vertices hold a coin: coins[i] is 1 if vertex i holds a coin and 0 otherwise. The distance between two vertices is the number of edges on the unique path between them. Standing at a vertex x , Alex collects every coin that lies at distance at most 2 from x (this includes a coin at x itself, at a neighbour of x , and at a neighbour of a neighbour). Alex picks one vertex, walks along edges, and must finish at the vertex he started from. An edge may be traversed any number of times, and all edges are bidirectional. A coin is collected as soon as Alex stands at some vertex within distance 2 of it. Find the smallest number of edge traversals in such a closed walk that collects every coin. Complete the function getMinPath with the following parameters: coins : array of tree_nodes inte