# 1665. Minimum Initial Energy to Finish Tasks

<https://leetcode.com/problems/minimum-initial-energy-to-finish-tasks>

## Description

You are given an array `tasks` where `tasks[i] = [actuali, minimumi]`:

* `actuali` is the actual amount of energy you **spend to finish** the `ith` task.
* `minimumi` is the minimum amount of energy you **require to begin** the `ith` task.

For example, if the task is `[10, 12]` and your current energy is `11`, you cannot start this task. However, if your current energy is `13`, you can complete this task, and your energy will be `3` after finishing it.

You can finish the tasks in **any order** you like.

Return *the **minimum** initial amount of energy you will need* *to finish all the tasks*.

**Example 1:**

```
**Input:** tasks = [[1,2],[2,4],[4,8]]
**Output:** 8
**Explanation:**
Starting with 8 energy, we finish the tasks in the following order:
    - 3rd task. Now energy = 8 - 4 = 4.
    - 2nd task. Now energy = 4 - 2 = 2.
    - 1st task. Now energy = 2 - 1 = 1.
Notice that even though we have leftover energy, starting with 7 energy does not work because we cannot do the 3rd task.
```

**Example 2:**

```
**Input:** tasks = [[1,3],[2,4],[10,11],[10,12],[8,9]]
**Output:** 32
**Explanation:**
Starting with 32 energy, we finish the tasks in the following order:
    - 1st task. Now energy = 32 - 1 = 31.
    - 2nd task. Now energy = 31 - 2 = 29.
    - 3rd task. Now energy = 29 - 10 = 19.
    - 4th task. Now energy = 19 - 10 = 9.
    - 5th task. Now energy = 9 - 8 = 1.
```

**Example 3:**

```
**Input:** tasks = [[1,7],[2,8],[3,9],[4,10],[5,11],[6,12]]
**Output:** 27
**Explanation:**
Starting with 27 energy, we finish the tasks in the following order:
    - 5th task. Now energy = 27 - 5 = 22.
    - 2nd task. Now energy = 22 - 2 = 20.
    - 3rd task. Now energy = 20 - 3 = 17.
    - 1st task. Now energy = 17 - 1 = 16.
    - 4th task. Now energy = 16 - 4 = 12.
    - 6th task. Now energy = 12 - 6 = 6.
```

**Constraints:**

* `1 <= tasks.length <= 105`
* `1 <= actual​i <= minimumi <= 104`

## ac

```java
```