CriticalRiver Interview Questions and Answers

Given a string, find the longest palindromic substring, prioritizing the one with the smallest start index.

• Iterate through the string and expand around each character to find palindromes

• Keep track of the longest palindrome found and its starting index

• Return the longest palindromic substring with the smallest start index

The task is to partition an array into two subsets such that the absolute difference between subset sums is minimum.

• Iterate through all possible subsets of the array

• Calculate the sum of each subset

• Find the minimum absolute difference between the subset sums

The task is to reverse a given doubly linked list and return the head of the modified list.

• Create three pointers: prev, current, and next.

• Iterate through the linked list and update the next and prev pointers for each node.

• Finally, update the head pointer to the last node visited and return it as the head of the reversed list.

Count the total instances of equivalent prime groups in a day divided into equal parts.

• Divide the day into equal parts and check for prime groups at the same position in different parts.

• Each prime group should consist of prime numbers occurring at different parts of the day.

• Return the total number of equivalent prime groups found.

• Example: For DAY_HOURS = 20 and PARTS = 2, there are 2 prime groups: 3-13 and 7-17.

Find the third largest element in an array of distinct integers.

• Sort the array in descending order and return the element at index 2.

• Handle cases where there are less than 3 elements in the array.

• Consider edge cases like negative integers and duplicates.

The task is to sort a list of integers based on their frequency of repetition, with the element with the highest frequency first.

• Count the frequency of each element in the list using a dictionary.

• Sort the elements based on their frequency in descending order.

• If two elements have the same frequency, maintain their original order.

• Return the sorted list.

The task is to find the number of distinct ways to move from the 0th to the Nth stair by ascending one or two steps at a time.

• Use dynamic programming to solve this problem efficiently.

• The number of ways to reach the Nth stair is the sum of the number of ways to reach the (N-1)th stair and the number of ways to reach the (N-2)th stair.

• Handle base cases for N=0 and N=1 separately.

• Consider using memoization to avoid redundant calculations.

• Example: For N=3, the number of distinct...read more