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# 1936. Add Minimum Number of Rungs

<https://leetcode.com/problems/add-minimum-number-of-rungs>

## Description

You are given a **strictly increasing** integer array `rungs` that represents the **height** of rungs on a ladder. You are currently on the **floor** at height `0`, and you want to reach the last rung.

You are also given an integer `dist`. You can only climb to the next highest rung if the distance between where you are currently at (the floor or on a rung) and the next rung is **at most** `dist`. You are able to insert rungs at any positive **integer** height if a rung is not already there.

Return *the **minimum** number of rungs that must be added to the ladder in order for you to climb to the last rung.*

**Example 1:**

```
**Input:** rungs = [1,3,5,10], dist = 2
**Output:** 2
**Explanation:**You currently cannot reach the last rung.
Add rungs at heights 7 and 8 to climb this ladder. 
The ladder will now have rungs at [1,3,5,7,8,10].
```

**Example 2:**

```
**Input:** rungs = [3,6,8,10], dist = 3
**Output:** 0
**Explanation:**
This ladder can be climbed without adding additional rungs.
```

**Example 3:**

```
**Input:** rungs = [3,4,6,7], dist = 2
**Output:** 1
**Explanation:**
You currently cannot reach the first rung from the ground.
Add a rung at height 1 to climb this ladder.
The ladder will now have rungs at [1,3,4,6,7].
```

**Example 4:**

```
**Input:** rungs = [5], dist = 10
**Output:** 0
**Explanation:**
This ladder can be climbed without adding additional rungs.
```

**Constraints:**

* `1 <= rungs.length <= 105`
* `1 <= rungs[i] <= 109`
* `1 <= dist <= 109`
* `rungs` is **strictly increasing**.

## ac

```java
```