2079\. Watering Plants

Medium

You want to water `n` plants in your garden with a watering can. The plants are arranged in a row and are labeled from `0` to `n - 1` from left to right where the <code>i<sup>th</sup></code> plant is located at `x = i`. There is a river at `x = -1` that you can refill your watering can at.

Each plant needs a specific amount of water. You will water the plants in the following way:

*   Water the plants in order from left to right.
*   After watering the current plant, if you do not have enough water to **completely** water the next plant, return to the river to fully refill the watering can.
*   You **cannot** refill the watering can early.

You are initially at the river (i.e., `x = -1`). It takes **one step** to move **one unit** on the x-axis.

Given a **0-indexed** integer array `plants` of `n` integers, where `plants[i]` is the amount of water the <code>i<sup>th</sup></code> plant needs, and an integer `capacity` representing the watering can capacity, return _the **number of steps** needed to water all the plants_.

**Example 1:**

**Input:** plants = [2,2,3,3], capacity = 5

**Output:** 14

**Explanation:** Start at the river with a full watering can:

- Walk to plant 0 (1 step) and water it. Watering can has 3 units of water.

- Walk to plant 1 (1 step) and water it. Watering can has 1 unit of water.

- Since you cannot completely water plant 2, walk back to the river to refill (2 steps).

- Walk to plant 2 (3 steps) and water it. Watering can has 2 units of water.

- Since you cannot completely water plant 3, walk back to the river to refill (3 steps).

- Walk to plant 3 (4 steps) and water it.

Steps needed = 1 + 1 + 2 + 3 + 3 + 4 = 14.

**Example 2:**

**Input:** plants = [1,1,1,4,2,3], capacity = 4

**Output:** 30

**Explanation:** Start at the river with a full watering can:

- Water plants 0, 1, and 2 (3 steps). Return to river (3 steps).

- Water plant 3 (4 steps). Return to river (4 steps).

- Water plant 4 (5 steps). Return to river (5 steps).

- Water plant 5 (6 steps).

Steps needed = 3 + 3 + 4 + 4 + 5 + 5 + 6 = 30.

**Example 3:**

**Input:** plants = [7,7,7,7,7,7,7], capacity = 8

**Output:** 49

**Explanation:** You have to refill before watering each plant.

Steps needed = 1 + 1 + 2 + 2 + 3 + 3 + 4 + 4 + 5 + 5 + 6 + 6 + 7 = 49.

**Constraints:**

*   `n == plants.length`
*   `1 <= n <= 1000`
*   <code>1 <= plants[i] <= 10<sup>6</sup></code>
*   <code>max(plants[i]) <= capacity <= 10<sup>9</sup></code>