Merge Overlapping Intervals in DSA Python - Build from Scratch

Merge Overlapping Intervals

📖 Scenario: You are organizing a schedule of meetings represented as time intervals. Some meetings overlap, and you want to combine these overlapping meetings into one to avoid conflicts.

🎯 Goal: Build a program that merges overlapping intervals from a list of meeting times.

📋 What You'll Learn

Create a list of intervals with exact values

Create a variable to hold the merged intervals

Write logic to merge overlapping intervals

Print the merged intervals in the specified format

💡 Why This Matters

🌍 Real World

Merging overlapping intervals is useful in calendar apps, booking systems, and resource scheduling to avoid conflicts.

💼 Career

Understanding interval merging helps in software development roles involving scheduling, data processing, and algorithm design.

1

Create the list of intervals

Create a list called intervals with these exact intervals: [1, 3], [2, 6], [8, 10], [15, 18]

DSA Python

# Create the list of intervals
# Your code here

Hint

Use a list of lists to represent intervals.

2

Create a list to hold merged intervals

Create an empty list called merged to store the merged intervals

DSA Python

intervals = [[1, 3], [2, 6], [8, 10], [15, 18]]
# Create an empty list called merged
# Your code here

Hint

This list will hold the final merged intervals.

3

Write logic to merge overlapping intervals

Sort the intervals list by the start time using intervals.sort(). Then use a for loop with variable interval to iterate over intervals. Inside the loop, if merged is empty or the end of the last interval in merged is less than the start of interval, append interval to merged. Otherwise, update the end of the last interval in merged to be the maximum of its current end and the end of interval.

DSA Python

intervals = [[1, 3], [2, 6], [8, 10], [15, 18]]
merged = []
# Sort intervals and merge overlapping ones
# Your code here

Hint

Sorting helps to compare intervals in order. Use merged[-1] to access the last merged interval.

4

Print the merged intervals

Print the merged list to display the merged intervals

DSA Python

intervals = [[1, 3], [2, 6], [8, 10], [15, 18]]
merged = []
intervals.sort()
for interval in intervals:
    if not merged or merged[-1][1] < interval[0]:
        merged.append(interval)
    else:
        merged[-1][1] = max(merged[-1][1], interval[1])
# Print the merged intervals
# Your code here

Hint

The output should show the merged intervals as a list of lists.