Ace the Algorithm: Coding Interview Challenge Quiz Quiz

1. Triplet Sum Zero

   Which of the following approaches is most efficient for finding all triplets in an array that sum to zero?

   1. A: Brute-force (three nested loops)
   2. B: Sorting the array and using two pointers
   3. C: Using a hash map to store all possible sums
   4. D: Recursively checking all possible combinations
   5. E: Converting the array to a string and searching for '0'

2. Binary String Generation

   Given a pattern string with '0', '1', and '?', where '?' can be '0' or '1', how many distinct binary strings can be generated from the pattern '1?0?'?

   1. A: 1
   2. B: 2
   3. C: 3
   4. D: 4
   5. E: Infinitely many

3. String Count Constraints

   How many strings of length 3 can be formed using 'a', 'b', and 'c', if the number of 'a's must be equal to the number of 'b's?

   1. A: 3
   2. B: 6
   3. C: 7
   4. D: 9
   5. E: 27

4. Largest Dictionary Word

   Given the string 'abppplee' and a dictionary ['apple', 'able', 'ale', 'ple'], which is the largest word in the dictionary that can be formed by deleting some characters from 'abppplee'?

   1. A: apple
   2. B: able
   3. C: ale
   4. D: ple
   5. E: apl

5. Subarray with Given Sum

   What is the most efficient approach to find a contiguous subarray with a given sum in an array of non-negative numbers?

   1. A: Brute-force (checking all possible subarrays)
   2. B: Using Kadane's algorithm
   3. C: Sorting the array first
   4. D: Using a sliding window technique
   5. E: Converting to a linked list

6. Longest Substring with K Unique Characters

   Given the string 'aabacbebebe' and k = 3, what is the length of the longest substring with exactly 3 unique characters?

   1. A: 4
   2. B: 5
   3. C: 7
   4. D: 10
   5. E: 11

7. Non-Repeating Elements

   In an array where all elements appear twice except for two elements that appear once, which bitwise operation can be used efficiently to find the two non-repeating elements?

   1. A: AND
   2. B: OR
   3. C: XOR
   4. D: NOT
   5. E: Left Shift

8. Flood Fill Algorithm

   In the Flood Fill algorithm, what data structure is typically used to keep track of the pixels to be filled?

   1. A: Stack
   2. B: Queue
   3. C: Tree
   4. D: Graph
   5. E: Linked List

9. Meta Strings

   Two strings are meta-strings if they can become equal after a single swap of characters in one of the strings. Are 'geeks' and 'keegs' meta-strings?

   1. A: Yes
   2. B: No
   3. C: Maybe
   4. D: Cannot be determined
   5. E: Only if the length is greater than 5

10. Unbounded Knapsack

    In the unbounded knapsack problem, can an item be selected multiple times?

    1. A: Yes
    2. B: No
    3. C: Only if the item's weight is less than the knapsack capacity
    4. D: Only if the item's value is greater than all other items
    5. E: Only if it's a fractional knapsack