1499. Max Value of Equation

https://leetcode.com/problems/max-value-of-equation

Description

You are given an array points containing the coordinates of points on a 2D plane, sorted by the x-values, where points[i] = [xi, yi] such that xi < xj for all 1 <= i < j <= points.length. You are also given an integer k.

Return the maximum value of the equation yi + yj + |xi - xj| where |xi - xj| <= k and 1 <= i < j <= points.length.

It is guaranteed that there exists at least one pair of points that satisfy the constraint |xi - xj| <= k.

Example 1:

**Input:** points = [[1,3],[2,0],[5,10],[6,-10]], k = 1
**Output:** 4
**Explanation:** The first two points satisfy the condition |xi - xj| <= 1 and if we calculate the equation we get 3 + 0 + |1 - 2| = 4. Third and fourth points also satisfy the condition and give a value of 10 + -10 + |5 - 6| = 1.
No other pairs satisfy the condition, so we return the max of 4 and 1.

Example 2:

**Input:** points = [[0,0],[3,0],[9,2]], k = 3
**Output:** 3
**Explanation:** Only the first two points have an absolute difference of 3 or less in the x-values, and give the value of 0 + 0 + |0 - 3| = 3.

Constraints:

• 2 <= points.length <= 105

• points[i].length == 2

• -108 <= xi, yi <= 108

• 0 <= k <= 2 * 108

• xi < xj for all 1 <= i < j <= points.length

• xi form a strictly increasing sequence.

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