10+ FIS Interview Questions and Answers

Count the number of unique paths from top left to bottom right in a binary tree.

• Use dynamic programming to keep track of the number of paths at each node.

• At each node, the number of paths is the sum of the number of paths from the node to the right and the node below.

• Example: For a 2x2 binary tree, there are 2 unique paths.

Find the maximum triplet sum satisfying given conditions

• Sort the array in ascending order

• Iterate through the array and keep track of the maximum triplet sum meeting the conditions

• Return the maximum triplet sum found

The coin change problem involves finding the number of ways to make a certain value using a given set of coins.

• Use dynamic programming to solve the coin change problem efficiently.

• Create a 1D array to store the number of ways to make each value from 0 to the target value.

• Iterate through the coins and update the array based on the current coin's value.

• The final answer will be stored in the last element of the array.

• Example: For target value 5 and coins [1, 2, 5], there are 4 w...read more

Rotate an array by K positions to the right

• Create a new array and copy elements from original array starting from index (n-k) to n-1, then copy elements from index 0 to (n-k-1)

• Alternatively, reverse the entire array, then reverse the first k elements and the remaining n-k elements separately

• Handle cases where k is greater than array length by taking modulo of k with array length

LFU (Least Frequently Used) cache is a data structure that removes the least frequently used items when the cache is full.

• LFU cache stores key-value pairs with a frequency count to track usage.

• When a new item is added, its frequency count is set to 1.

• When an existing item is accessed, its frequency count is incremented.

• When the cache is full, the item with the lowest frequency count is removed.

• Example: If cache size is 3 and items are accessed in the order A, B, A, C, A, B, t...read more

Use recursion to generate all possible permutations of a given string.

• Use recursion to swap characters in the string to generate permutations

• Keep track of visited characters to avoid duplicates

• Base case: when the length of the string is 1, add it to the result array

Finding nodes at a distance of K from the current node in a tree/graph.

• Use BFS/DFS to traverse the tree/graph.

• Maintain a visited set to avoid revisiting nodes.

• Keep track of the distance of each node from the current node.

• Return all nodes at a distance of K from the current node.

SQL query to retrieve total sales amount by product category

• Use GROUP BY clause to group the results by product category

• Use SUM() function to calculate the total sales amount

• Join the tables if necessary to get the required data

Design a yin yang using css

• Create a circle using border-radius property

• Use background-color to fill the circle with black and white

• Create two smaller circles inside the main circle using absolute positioning

• Use transform property to rotate the smaller circles

• Add box-shadow to create the 3D effect