150 Most Frequently Asked Questions On Quant Interviews -

: In a sequence of n coin flips, what is the expected number of runs (consecutive same outcomes)?

How can it be solved analytically or numerically?

Roll a die. You can either take the dollar amount of the roll, or pay $1 to roll again (up to 3 total rolls). What is your optimal strategy and expected payoff? 150 Most Frequently Asked Questions On Quant Interviews

: How do you detect data leakage in a machine learning pipeline?

: It spans a vast spectrum of quantitative knowledge, including: Mathematics : Calculus, differential equations, and linear algebra. Probability & Statistics : In a sequence of n coin flips,

: How do estimated beta coefficients and t-statistics change if each sample is duplicated?

Probability forms the bedrock of quantitative trading and research. Interviewers use these questions to test your ability to think clearly under pressure when dealing with uncertainty. Dice, Coins, and Cards You can either take the dollar amount of

: What are rvalue references and move constructors? Why are they important for performance?

| # | Question | Difficulty | Key Idea | |---|----------|------------|-----------| | 116 | Write a function to compute Fibonacci numbers efficiently. | ★ | Memoization or iteration | | 117 | What is the difference between a list and a tuple in Python? | ★ | Mutable vs immutable | | 118 | How do you reverse a linked list? | ★★ | Iterate with prev/next | | 119 | What is the complexity of quicksort? | ★ | Avg O(n log n), worst O(n²) | | 120 | What is a hash table? | ★ | O(1) average lookup | | 121 | Write a function to check if a string is a palindrome. | ★ | Two pointers | | 122 | What is recursion? Example. | ★ | Function calling itself | | 123 | What is the difference between depth-first and breadth-first search? | ★ | Stack vs queue | | 124 | What is a binary search tree? | ★ | Left < root < right | | 125 | How do you detect a cycle in a linked list? | ★★ | Floyd’s cycle detection | | 126 | What is dynamic programming? | ★★ | Overlapping subproblems | | 127 | Write a function to compute the nth prime. | ★★ | Sieve of Eratosthenes | | 128 | What is the difference between a process and a thread? | ★ | Separate memory vs shared | | 129 | What is a deadlock? | ★★ | Mutual waiting | | 130 | What is the difference between map and reduce ? | ★ | Apply vs aggregate | | 131 | How do you sort a large file that doesn’t fit in memory? | ★★ | External sort | | 132 | What is a generator in Python? | ★ | Lazy iteration using yield | | 133 | What is a decorator? | ★★ | Wrapper function | | 134 | What is the GIL in Python? | ★★ | Global interpreter lock | | 135 | Write a function to compute the dot product of two vectors. | ★ | sum(a*b for a,b in zip(v1,v2)) |

(Kadane's Algorithm). Explain time and space complexity.