Day 2 of 133
Distributions you'll see in interviews + DSA Arrays/Hashing
Bernoulli/Binomial/Poisson/Normal/Exponential. CLT intuition. More NeetCode arrays/hashing.
DSA · NeetCode Arrays & Hashing
- Group AnagramsDSA · Arrays & Hashing
Interview questions to prep
- What's your hash key — sorted string vs character-count tuple? Trade-offs?
- How does this scale to a streaming input where new strings keep arriving?
- Top K Frequent ElementsDSA · Arrays & Hashing
Interview questions to prep
- Walk through bucket sort (O(n)) vs heap of k (O(n log k)) — when does each win?
- What if k is much larger than the unique-element count?
- Encode And Decode StringsDSA · Arrays & Hashing
Interview questions to prep
- What's the time and space complexity? Where can you tighten it?
- Walk through edge cases: empty input, single element, all duplicates, negatives.
- Why is a hash map / hash set the right structure here? When would a sorted structure beat it?
Math · Distributions you'll see in interviews
Interview questions to prep
- When should you model click events as Bernoulli vs Poisson?
- Derive the mean and variance of a Binomial(n, p).
- Why does the Poisson approximate the Binomial when n is large and p small?
Interview questions to prep
- Why is the Normal so common — what's the Central Limit Theorem intuition?
- When would you pick a Beta distribution over a Normal?
- How is the Exponential distribution memoryless, and why does that matter for modeling time-to-event?
Interview questions to prep
- State the Central Limit Theorem precisely and explain what it does NOT say.
- How does the CLT justify using normal-based confidence intervals on means?
- When does the CLT fail or converge slowly?
References & further reading