Technical Examples (Exam-Oriented Understanding)

This section helps you connect the concept with real exam-level questions and strengthens your problem-solving approach.

Standard Problem (Most Important)

Problem:
Find the maximum number of consecutive 1s if you can flip at most K zeros.

Approach:

• Use sliding window
• Maintain at most 2 zeros

Answer: 7

Variation 1 (Longest Substring with K Replacements)

Given a string:

You can replace at most K characters to make all characters the same.

Answer: 4

✔ Same logic:

• Maintain a window
• Limit changes ≤ K
• Variation 2 (Max Consecutive Ones III)

Classic problem (very important)

Flip at most 2 zeros

Answer: 5

Variation 3 (Longest Subarray with At Most K Zeros)

Direct form of this problem:

Answer: 5

✔ Same pattern:

• Count zeros
• Maintain window

Variation 4 (At Most K Distinct Elements)

Example:

Longest subarray with at most 2 distinct numbers

Answer: 4

✔ Difference:

• Instead of zeros → track distinct elements

Pattern Recognition (Very Important for Exams)

Whenever you see questions like:

• “Longest subarray…”
• “At most K…”
• “Maximum continuous…”