Class Solution


  • public class Solution
    extends Object
    1443 - Minimum Time to Collect All Apples in a Tree.

    Medium

    Given an undirected tree consisting of n vertices numbered from 0 to n-1, which has some apples in their vertices. You spend 1 second to walk over one edge of the tree. Return the minimum time in seconds you have to spend to collect all apples in the tree, starting at vertex 0 and coming back to this vertex.

    The edges of the undirected tree are given in the array edges, where edges[i] = [ai, bi] means that exists an edge connecting the vertices ai and bi. Additionally, there is a boolean array hasApple, where hasApple[i] = true means that vertex i has an apple; otherwise, it does not have any apple.

    Example 1:

    Input: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,true,true,false]

    Output: 8

    Explanation: The figure above represents the given tree where red vertices have an apple. One optimal path to collect all apples is shown by the green arrows.

    Example 2:

    Input: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,true,false,false,true,false]

    Output: 6

    Explanation: The figure above represents the given tree where red vertices have an apple. One optimal path to collect all apples is shown by the green arrows.

    Example 3:

    Input: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], hasApple = [false,false,false,false,false,false,false]

    Output: 0

    Constraints:

    • 1 <= n <= 105
    • edges.length == n - 1
    • edges[i].length == 2
    • 0 <= ai < bi <= n - 1
    • fromi < toi
    • hasApple.length == n
    • Constructor Detail

      • Solution

        public Solution()
    • Method Detail

      • minTime

        public int minTime​(int n,
                           int[][] edges,
                           List<Boolean> hasApple)