# 1443. Minimum Time to Collect All Apples in a Tree

<https://leetcode.com/problems/minimum-time-to-collect-all-apples-in-a-tree>

## Description

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:**

![](https://assets.leetcode.com/uploads/2020/04/23/min_time_collect_apple_1.png)

```
**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:**

![](https://assets.leetcode.com/uploads/2020/04/23/min_time_collect_apple_2.png)

```
**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`

## ac

```java
```