Meeting Rooms II

Medium

Given meeting intervals (each [start, end]), return the minimum number of conference rooms required.

Example 1

Input:  grid = [[0,30],[5,10],[15,20]]
Output: 2

Example 2

Input:  grid = [[7,10],[2,4]]
Output: 1

Constraints

• 1 <= intervals.length <= 10^4
• intervals[i].length == 2