Insert Interval into Sorted List in DSA Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main goal when inserting a new interval into a sorted list of intervals?

To add the new interval into the list so that the list remains sorted and any overlapping intervals are merged into one.

beginner

How do you know if two intervals overlap?

Two intervals overlap if the start of one interval is less than or equal to the end of the other interval, and vice versa.

intermediate

Why do we merge intervals when inserting a new interval into a sorted list?

Merging prevents overlapping intervals from appearing separately, keeping the list clean and representing continuous ranges correctly.

intermediate

What is the time complexity of inserting an interval into a sorted list and merging overlaps?

The time complexity is O(n), where n is the number of intervals, because we may need to check and merge intervals sequentially.

beginner

In the context of interval insertion, what does it mean for the list to be sorted?

The intervals are sorted by their start times in ascending order, which helps in efficiently finding where to insert and merge the new interval.

What should you do if the new interval does not overlap with any existing intervals?

A Insert it in the correct position to keep the list sorted

B Merge it with the first interval

C Discard the new interval

D Replace the last interval with the new one

If there is no overlap, the new interval should be inserted in the correct sorted position.

Which condition indicates two intervals [a, b] and [c, d] overlap?

A b < c

B a > d

C a > b

D b >= c and a <= d

Intervals overlap if the end of the first is at least the start of the second and the start of the first is at most the end of the second.

What is the first step when inserting a new interval into a sorted list?

A Sort the list again

B Merge all intervals first

C Find the position where the new interval fits based on start time

D Remove all intervals

You first find where the new interval fits to keep the list sorted.

After merging overlapping intervals, what is true about the list?

A It may have overlapping intervals

B It remains sorted and has no overlapping intervals

C It is unsorted

D It contains duplicates

Merging ensures the list stays sorted and free of overlapping intervals.

What data structure is commonly used to represent intervals?

A List of two elements [start, end]

B Single integer

C String

D Boolean

Intervals are usually represented as lists or arrays with two elements: start and end.

Explain how to insert a new interval into a sorted list of intervals and merge any overlaps.

Think about scanning the list and combining intervals that touch or overlap.

Describe the conditions that determine if two intervals overlap and why merging is necessary.

Focus on the start and end points and what happens if intervals overlap.