1840. Maximum Building Height

https://leetcode.com/problems/maximum-building-height

Description

You want to build n new buildings in a city. The new buildings will be built in a line and are labeled from 1 to n.

However, there are city restrictions on the heights of the new buildings:

• The height of each building must be a non-negative integer.

• The height of the first building must be 0.

• The height difference between any two adjacent buildings cannot exceed 1.

Additionally, there are city restrictions on the maximum height of specific buildings. These restrictions are given as a 2D integer array restrictions where restrictions[i] = [idi, maxHeighti] indicates that building idi must have a height less than or equal to maxHeighti.

It is guaranteed that each building will appear at most once in restrictions, and building 1 will not be in restrictions.

Return the maximum possible height of the tallest building.

Example 1:

**Input:** n = 5, restrictions = [[2,1],[4,1]]
**Output:** 2
**Explanation:** The green area in the image indicates the maximum allowed height for each building.
We can build the buildings with heights [0,1,2,1,2], and the tallest building has a height of 2.

Example 2:

**Input:** n = 6, restrictions = []
**Output:** 5
**Explanation:** The green area in the image indicates the maximum allowed height for each building.
We can build the buildings with heights [0,1,2,3,4,5], and the tallest building has a height of 5.

Example 3:

**Input:** n = 10, restrictions = [[5,3],[2,5],[7,4],[10,3]]
**Output:** 5
**Explanation:** The green area in the image indicates the maximum allowed height for each building.
We can build the buildings with heights [0,1,2,3,3,4,4,5,4,3], and the tallest building has a height of 5.

Constraints:

• 2 <= n <= 109

• 0 <= restrictions.length <= min(n - 1, 105)

• 2 <= idi <= n

• idi is unique.

• 0 <= maxHeighti <= 109

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