Skip to main content

Coding Interview Questions

Review this list of 430 Coding interview questions and answers verified by hiring managers and candidates.
  • 17 answers
    +14

    "Required output in the solution not the one requested from the question. only customerid, firstname, last_name and years were required. Please this needs to be very clear. Otherwise my answer is with totalorderyear as ( SELECT o.customer_id, c.first_name, c.last_name, EXTRACT(YEAR FROM o.orderdate) AS orderyear, COUNT(o.orderid) AS totalorders FROM orders o LEFT JOIN customers c ON c.customerid = o.customerid GROUP BY o.customerid, c.firstname, c.last"

    Gloriose H. - "Required output in the solution not the one requested from the question. only customerid, firstname, last_name and years were required. Please this needs to be very clear. Otherwise my answer is with totalorderyear as ( SELECT o.customer_id, c.first_name, c.last_name, EXTRACT(YEAR FROM o.orderdate) AS orderyear, COUNT(o.orderid) AS totalorders FROM orders o LEFT JOIN customers c ON c.customerid = o.customerid GROUP BY o.customerid, c.firstname, c.last"See full answer

    Coding
    SQL
  • Amazon logoAsked at Amazon 
    7 answers
    +3

    "General Approach (using Max-Heap) Use a max-heap (priority queue) of size k. For each point: Compute the distance to P. Push it into the heap. If heap size > k, remove the farthest point. The heap will contain the k closest points to P. import java.util.*; public class KClosestPoints { static class Point { int x, y; public Point(int x, int y) { this.x = x; this.y = y; } // Euclidean distance squared (no need to take square root) p"

    Khushbu R. - "General Approach (using Max-Heap) Use a max-heap (priority queue) of size k. For each point: Compute the distance to P. Push it into the heap. If heap size > k, remove the farthest point. The heap will contain the k closest points to P. import java.util.*; public class KClosestPoints { static class Point { int x, y; public Point(int x, int y) { this.x = x; this.y = y; } // Euclidean distance squared (no need to take square root) p"See full answer

    Software Engineer
    Coding
    +2 more
  • Google logoAsked at Google 
    Add answer
    Software Engineer
    Coding
    +1 more
  • Meta logoAsked at Meta 
    5 answers
    +2

    "Implemented a recursive function which returns the length of the list so far. when the returned value equals k + 1 , assign current.next = current.next.next. If I made it back to the head return root.next as the new head of the linked list."

    דניאל ר. - "Implemented a recursive function which returns the length of the list so far. when the returned value equals k + 1 , assign current.next = current.next.next. If I made it back to the head return root.next as the new head of the linked list."See full answer

    Machine Learning Engineer
    Coding
    +2 more
  • Amazon logoAsked at Amazon 
    2 answers
    Video answer for 'Build an image carousel that displays a sequence of images (using React.js or vanilla JS).'

    "Started by asking clarification questions regarding design constraints and desired features. Break down the into re-usable components - HeroImg and Carousel (with 3 images rendered) Code the components and managed the state for both in the parent component."

    Akshay J. - "Started by asking clarification questions regarding design constraints and desired features. Break down the into re-usable components - HeroImg and Carousel (with 3 images rendered) Code the components and managed the state for both in the parent component."See full answer

    Frontend Engineer
    Coding
  • 🧠 Want an expert answer to a question? Saving questions lets us know what content to make next.

  • 28 answers
    +25

    "select name, stock from products p left join transactions t on p.id = t.product_id order by date desc limit 1"

    Daniel C. - "select name, stock from products p left join transactions t on p.id = t.product_id order by date desc limit 1"See full answer

    Data Engineer
    Coding
    +3 more
  • 19 answers
    Video answer for 'E-commerce (1 of 5)'
    +16

    "select sum(orderquantity) as totalunitsorderedyesterday from orders as ord join items as it on ord.itemid=it.itemid where order_date="2023-10-14""

    Rudra pratap S. - "select sum(orderquantity) as totalunitsorderedyesterday from orders as ord join items as it on ord.itemid=it.itemid where order_date="2023-10-14""See full answer

    Coding
    SQL
  • "Build a counter using queue, one queue per service ("a", "b") and one with just timestamps to get the overall load. Build rate limiter service using the counter and interviewer asked if there rate limiter might use a different instance of a counter"

    Chethan N. - "Build a counter using queue, one queue per service ("a", "b") and one with just timestamps to get the overall load. Build rate limiter service using the counter and interviewer asked if there rate limiter might use a different instance of a counter"See full answer

    Software Engineer
    Coding
  • "I would assume that this is similar to an intervals question. Meeting Rooms II (https://www.lintcode.com/problem/919/?fromId=203&_from=collection) on Leetcode seems like the closest comparison, it's a premium question so I linked Lintcode. I'm assuming that we also need to just return the minimum number of cars used. You need to sort for the most optimal solution, so you're constrained by an O(nlogn) time complexity. So any sorting solution could work (using a heap, sorting the array input arra"

    Sohum S. - "I would assume that this is similar to an intervals question. Meeting Rooms II (https://www.lintcode.com/problem/919/?fromId=203&_from=collection) on Leetcode seems like the closest comparison, it's a premium question so I linked Lintcode. I'm assuming that we also need to just return the minimum number of cars used. You need to sort for the most optimal solution, so you're constrained by an O(nlogn) time complexity. So any sorting solution could work (using a heap, sorting the array input arra"See full answer

    Software Engineer
    Coding
    +1 more
  • Software Engineer
    Coding
    +1 more
  • Adobe logoAsked at Adobe 
    34 answers
    +30

    "In python def find_duplicates(arr1: List[int], arr2: List[int]) -> List[int]: result = list(set(arr1) & set(arr2)) return result "

    Sammy R. - "In python def find_duplicates(arr1: List[int], arr2: List[int]) -> List[int]: result = list(set(arr1) & set(arr2)) return result "See full answer

    Data Engineer
    Coding
    +2 more
  • Amazon logoAsked at Amazon 
    2 answers
    Video answer for 'Implement k-means clustering.'

    "at first I want to know number of cluster I will put random number if I don't know and I will use method called Elbow method or Silhouette Score ,Gap Statistic and Davies–Bouldin Index to know the best number of cluster and I will use scikit-learn library to import kmeans from sklearn.cluster import KMeans kmeans = KMeans(nclusters=2, randomstate=0) kmeans.fit(X) and X this my data "

    Taheia S. - "at first I want to know number of cluster I will put random number if I don't know and I will use method called Elbow method or Silhouette Score ,Gap Statistic and Davies–Bouldin Index to know the best number of cluster and I will use scikit-learn library to import kmeans from sklearn.cluster import KMeans kmeans = KMeans(nclusters=2, randomstate=0) kmeans.fit(X) and X this my data "See full answer

    Machine Learning Engineer
    Coding
    +5 more
  • +1

    "Binary serach on E range"

    Shikha S. - "Binary serach on E range"See full answer

    Software Engineer
    Coding
    +1 more
  • Microsoft logoAsked at Microsoft 
    3 answers

    "Let me try to explain it with simple life analogy You're cooking dinner in the kitchen. Multithreading is when you've got a bunch of friends helping out. Each friend does a different job—like one chops veggies while another stirs a sauce. Everyone focuses on their task, and together, you all make the meal faster. In a computer, it's like different jobs happening all at once, making stuff happen quicker, just like having lots of friends helping makes dinner ready faster."

    Praveen D. - "Let me try to explain it with simple life analogy You're cooking dinner in the kitchen. Multithreading is when you've got a bunch of friends helping out. Each friend does a different job—like one chops veggies while another stirs a sauce. Everyone focuses on their task, and together, you all make the meal faster. In a computer, it's like different jobs happening all at once, making stuff happen quicker, just like having lots of friends helping makes dinner ready faster."See full answer

    Software Engineer
    Coding
    +1 more
  • Google logoAsked at Google 
    7 answers
    Video answer for 'Write functions to serialize and deserialize a list of strings.'
    +4

    "One thing is not clear to me, We encoded the length of the word to a character, but the max number which can be converted to char ascii is 255. How will it work for length till 65535?"

    Curly T. - "One thing is not clear to me, We encoded the length of the word to a character, but the max number which can be converted to char ascii is 255. How will it work for length till 65535?"See full answer

    Software Engineer
    Coding
    +1 more
  • "How do you find consecutive days for login (MySQL, SQL, date, subquery, MySQL 5.7, development)? 1 Follow Request Answer More All related (34) Recommended 📷 Trausti Thor Johannsson · Follow Been using MySQL for more than 16 yearsDec 27 There are functions like DATEDIFF but there are also BETWE"

    Hayatu H. - "How do you find consecutive days for login (MySQL, SQL, date, subquery, MySQL 5.7, development)? 1 Follow Request Answer More All related (34) Recommended 📷 Trausti Thor Johannsson · Follow Been using MySQL for more than 16 yearsDec 27 There are functions like DATEDIFF but there are also BETWE"See full answer

    Data Engineer
    Coding
    +1 more
  • Amazon logoAsked at Amazon 
    13 answers
    +10

    "Without using a recursive approach, one can perform a post-order traversal by removing the parent nodes from the stack only if children were visited: def diameterOfTree(root): if root is None: return 0 diameter = 0 stack = deque([[root, False]]) # (node, visited) node_heights = {} while stack: curr_node, visited = stack[-1] if visited: heightleft = nodeheights.get(curr_node.left, 0) heightright = nodehe"

    Gabriele G. - "Without using a recursive approach, one can perform a post-order traversal by removing the parent nodes from the stack only if children were visited: def diameterOfTree(root): if root is None: return 0 diameter = 0 stack = deque([[root, False]]) # (node, visited) node_heights = {} while stack: curr_node, visited = stack[-1] if visited: heightleft = nodeheights.get(curr_node.left, 0) heightright = nodehe"See full answer

    Software Engineer
    Coding
    +2 more
  • Oracle logoAsked at Oracle 
    1 answer

    "Since a bitonic array first increases then decreases, we can: Find the peak using binary search (O(log n)) Reverse the decreasing half Merge the two sorted halvesThis gives an overall time complexity of O(n)."

    Krishnaveni G. - "Since a bitonic array first increases then decreases, we can: Find the peak using binary search (O(log n)) Reverse the decreasing half Merge the two sorted halvesThis gives an overall time complexity of O(n)."See full answer

    Engineering Manager
    Coding
    +1 more
  • Adobe logoAsked at Adobe 
    15 answers
    +10

    " function climbStairs(n) { // 4 iterations of Dynamic Programming solutions: // Step 1: Recursive: // if (n <= 2) return n // return climbStairs(n-1) + climbStairs(n-2) // Step 2: Top-down Memoization // const memo = {0:0, 1:1, 2:2} // function f(x) { // if (x in memo) return memo[x] // memo[x] = f(x-1) + f(x-2) // return memo[x] // } // return f(n) // Step 3: Bottom-up Tabulation // const tab = [0,1,2] // f"

    Matthew K. - " function climbStairs(n) { // 4 iterations of Dynamic Programming solutions: // Step 1: Recursive: // if (n <= 2) return n // return climbStairs(n-1) + climbStairs(n-2) // Step 2: Top-down Memoization // const memo = {0:0, 1:1, 2:2} // function f(x) { // if (x in memo) return memo[x] // memo[x] = f(x-1) + f(x-2) // return memo[x] // } // return f(n) // Step 3: Bottom-up Tabulation // const tab = [0,1,2] // f"See full answer

    Software Engineer
    Coding
    +3 more
  • Google logoAsked at Google 
    27 answers
    +23

    "def friend_distance(friends, userA, userB): step = 0 total_neighs = set() llen = len(total_neighs) total_neighs.add(userB) while len(total_neighs)!=llen: s = set() step += 1 llen = len(total_neighs) for el in total_neighs: nes = neighbours(friends, userA, el) if userA in nes: return step for p in nes: s.add(p) for el in s: total_neighs.add(el) return -1 def neighbours(A,n1, n2): out = set() for i in range(len(A[n2])): if An2: out.add(i) return out"

    Batman X. - "def friend_distance(friends, userA, userB): step = 0 total_neighs = set() llen = len(total_neighs) total_neighs.add(userB) while len(total_neighs)!=llen: s = set() step += 1 llen = len(total_neighs) for el in total_neighs: nes = neighbours(friends, userA, el) if userA in nes: return step for p in nes: s.add(p) for el in s: total_neighs.add(el) return -1 def neighbours(A,n1, n2): out = set() for i in range(len(A[n2])): if An2: out.add(i) return out"See full answer

    Software Engineer
    Coding
    +1 more
Showing 81-100 of 430