84. Largest Rectangle in Histogram

https://leetcode.com/problems/largest-rectangle-in-histogram/

Given an array of integers heights representing the histogram's bar height where the width of each bar is 1, return the area of the largest rectangle in the histogram.

Example 1

• Input: heights = [2,1,5,6,2,3]
• Output: 10
• Explanation: The above is a histogram where width of each bar is 1. The largest rectangle is shown in the red area, which has an area = 10 units.

Example 2

• Input: heights = [2,4]
• Output: 4

Constraints

• 1 <= heights.length <= 10^5
• 0 <= heights[i] <= 10^4