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Meeting Rooms

Easy · intervals

You are given a list intervals, where each item [start, end] is one meeting. A meeting occupies the time from start up to, but not including, end.

Return True if one person can attend every meeting, and False if at least two meetings overlap. A meeting that ends at the exact moment another one starts does not overlap it, so [1, 5] and [5, 9] are fine back to back.

The meetings come in no particular order, and the list can be empty (then the answer is True).

Examples

Example 1

Input: intervals = [[0, 30], [5, 10], [15, 20]]

Output: False

The meeting [0, 30] is still running when [5, 10] starts, so you cannot be at both.

Example 2

Input: intervals = [[7, 10], [2, 4]]

Output: True

The list is not sorted, but [2, 4] is over before [7, 10] begins.

Example 3

Input: intervals = [[1, 5], [5, 9], [9, 12]]

Output: True

Each meeting ends exactly when the next one starts. That is allowed.

Constraints

• 0 <= len(intervals) <= 10^4
• intervals[i] has exactly two numbers, start and end
• -10^6 <= start < end <= 10^6