Algofily

Coding interview prep that teaches patterns, not answers. Name the pattern, write the code, explain it 👇

[Algofily @algofilyHQ]

Reverse a String as a superhero mission: two pointers swap from both ends, then step in. Even length, they pass each other. Odd length, the middle letter stays put.

Boss level: what does SWAP become?

[Algofily @algofilyHQ]

@KrishnaBuildsAI Solid list. The part most people skip is the step between knowing the topic and spotting it in a new question. A quick habit that helps: before coding, say which pattern it is and why in one sentence. Sorted input plus a target? Probably two pointers or binary search.

[Algofily @algofilyHQ]

@yashmp2004 This is so real. Grinding hundreds of random problems and memorizing them falls apart the second the constraint changes. Naming the pattern first (and why it fits) is what actually survives a modified question.

[Algofily @algofilyHQ]

@arpit_bhayani Agree on skipping the theater. One thing that still helps even when you know the optimal: name the pattern and the tradeoff in one sentence before you code. Interviewers care that you chose it on purpose, not that you walked the scenic route.

[Algofily @algofilyHQ]

Valid Palindrome as a game: two pointers run in from both ends, hop the symbols, ignore case. One mismatch and it's game over.

Boss level: "Was it a car or a cat I saw?" Palindrome or not? 👇

[Algofily @algofilyHQ]

Merge Sorted Array in place: fill from the back.

The free space is at the end, so write the bigger number there first. O(m+n) time, O(1) space.

Quiz: if nums1 runs out first, what's left to do? 👇

[Algofily @algofilyHQ]

@Manvinder0987 Good luck today! One thing that helps in the OA: before you write any code, name the pattern and why it fits. If you're stuck between two, get a brute force passing first and then optimize. You've clearly put the work in 🤞

[Algofily @algofilyHQ]

Buy and Sell Stock is one variable: the lowest price so far.

Each day, profit = price minus that low. Keep the max.

Prices 3, 8, 2, 6. Max profit?

[Algofily @algofilyHQ]

@Giga_Goblin honestly 20 is the hard way 😅 most of those collapse into like 6 or 7 patterns. learn those and the 20 kind of take care of themselves

[Algofily @algofilyHQ]

@kiruthickrosan2 Day 3 and you already spotted the thing most people take months to see. Good next test: pick one you solved on day 1, close everything, and say the pattern in one sentence before you code. If it comes out easy, it stuck

[Algofily @algofilyHQ]

Valid Parentheses is just a stack.

Push openers, pop on closers, check the match.

Is {(}) valid? 👇

[Algofily @algofilyHQ]

@Axaxyx_ 100 days straight is no joke, congrats! we're building a pattern first interview prep tool and would love feedback from someone who just went through all of it. up for giving it a try?

[Algofily @algofilyHQ]

Two Sum in one question: have I already seen target minus this?

One pass, one hash map. Learn the pattern, not the answer.

[Algofily @algofilyHQ]

@offerscout Redo it a week later without peeking is the one almost nobody does, and it's the fastest way to tell if you learned the pattern or just the code. Fully agree on explaining the pattern over the answer

[Algofily @algofilyHQ]

@devXritesh The redo is the part people skip. Solving it once with the solution open feels like progress, coming back a week later cold is where you actually find out. Saying the pattern and why in one sentence before coding catches the gaps fast too

[Algofily @algofilyHQ]

@adigoyalll Not gone, just shifting. plenty of companies still run DSA rounds, so a refresh makes sense. you don't need to redo everything though, one or two problems a day, one per pattern, keeps it warm and still leaves time to build

[Algofily @algofilyHQ]

@devvxsagar Go one pattern at a time instead of random problems. do 3 or 4 of the same kind until you can spot it from the problem statement, then move on. and redo old ones without looking every week, that's where it actually sticks. good luck!

[Algofily @algofilyHQ]

@Shreyaazvp Stage 3 is where most of us live honestly 😅 quick way out: close the solution and say in one sentence why the approach works. if you can't yet, that's fine, it just tells you exactly what to go back to

[Algofily @algofilyHQ]

@tech_Ashish_ Don't try to pick up exactly where you left off. First week back, redo 5 or 6 problems you already solved, one per pattern, without looking. It brings the instinct back way faster than jumping into new ones, then go forward from there

[Algofily @algofilyHQ]

@agent_arjun_007 Easiest test we know: open a problem you solved a few weeks ago and before touching any code, say which pattern it is and why in one sentence. If you can, you learned it. If you just remember what the code looked like, you memorized it