1500+ Software Developer Interview Questions and Answers for Freshers

Implement a function to delete a node from a linked list at a specified position.

• Traverse the linked list to find the node at the specified position.

• Update the pointers of the previous and next nodes to skip the node to be deleted.

• Handle edge cases such as deleting the head or tail of the linked list.

• Ensure to free the memory of the deleted node to avoid memory leaks.

Find total distinct card types and common card types between two packs of cards.

• Create a set to store distinct card types when combining both packs.

• Iterate through each pack and add card types to the set.

• Find the intersection of card types between the two packs to get common card types.

Find the maximum sum of non-adjacent elements in an array.

• Use dynamic programming to keep track of the maximum sum at each index, considering whether to include the current element or skip it.

• At each index, the maximum sum is either the sum of the current element and the element two positions back, or the sum at the previous index.

• Iterate through the array and update the maximum sum at each index accordingly.

• Return the maximum sum obtained at the last index as the final resul...read more

Determine if an array can be transformed into a non-decreasing array by modifying at most one element.

• Iterate through the array and check if there are more than one decreasing elements.

• If there is only one decreasing element, check if modifying it can make the array non-decreasing.

• Return true if the array can be made non-decreasing by modifying at most one element, otherwise false.

Calculate the total volume of water that can be trapped in a 2-D elevation map after rain.

• Iterate over the matrix and find the maximum height on the borders.

• Calculate the water trapped at each cell by finding the difference between the cell's height and the minimum of its neighboring maximum heights.

• Sum up the trapped water for all cells to get the total volume of water trapped.

The task is to print two strings in an alternating sequence by indices.

• Iterate through both strings simultaneously and append characters alternately

• Handle the case where one string is longer than the other

• Use two pointers to keep track of the current index in each string

Check if a given matrix is idempotent by verifying if M * M = M.

• Iterate through the matrix and multiply it with itself to check if it equals the original matrix.

• If the condition M * M = M is satisfied, then the matrix is idempotent.

• If the condition is not satisfied, then the matrix is not idempotent.

Count the total number of palindromic substrings in a given string.

• Iterate through each character in the string and expand around it to find palindromic substrings.

• Use dynamic programming to store the results of subproblems to avoid redundant calculations.

• Consider both odd and even length palindromes while counting.

• Example: For input 'abbc', the palindromic substrings are ['a', 'b', 'b', 'c', 'bb'], totaling 5.

Calculate the sum of minimum and maximum elements of all subarrays of size K in an array.

• Iterate through the array and maintain a deque to store the indices of elements in the current window of size K.

• Keep track of the minimum and maximum elements in the current window using the deque.

• Calculate the sum of minimum and maximum elements for each subarray of size K and return the total sum.

The problem requires assigning aggressive cows to stalls in a way that maximizes the minimum distance between any two cows.

• Sort the array of stall positions in ascending order.

• Use binary search to find the largest minimum distance between cows.

• Check if it is possible to assign cows with this minimum distance by iterating through the sorted array.

• If it is possible, update the maximum distance and continue binary search for a larger minimum distance.

• Return the maximum distance ...read more

Find the longest palindromic substring in a given string, returning the rightmost one if multiple substrings are of the same length.

• Iterate through each character in the string and expand around it to find palindromic substrings

• Keep track of the longest palindromic substring found so far

• Return the rightmost longest palindromic substring

Find the length of the longest subarray with zero sum in an array of integers.

• Iterate through the array and keep track of the running sum using a hashmap.

• If the running sum is seen before, the subarray between the current index and the previous index with the same sum is a subarray with zero sum.

• Update the length of the longest subarray with zero sum as you iterate through the array.

• Example: For arr1 = [1, -1, 3, 2, -2, -3, 3], the longest subarray with zero sum is [3, 2, -2,...read more

Calculate the maximum number of unique vehicle registrations based on given constraints.

• Parse input for number of test cases, district count, letter ranges, and digit ranges.

• Calculate the total number of unique registrations based on the given constraints.

• Output the maximum number of unique vehicle registrations for each test case.

Reschedule at most K presentations to maximize longest gap without overlap.

• Iterate through presentations and calculate the gap between each pair of presentations

• Sort the presentations by their start times and keep track of the longest gap

• Reschedule at most K presentations to maximize the longest gap without overlap

Use matrix exponentiation to efficiently compute the Nth Fibonacci number modulo 10^9 + 7.

• Implement matrix exponentiation to calculate Fibonacci numbers efficiently.

• Use the formula F(n) = F(n-1) + F(n-2) with initial values F(1) = F(2) = 1.

• Return the result modulo 10^9 + 7 to handle large Fibonacci numbers.

• Optimize the solution to achieve better than O(N) time complexity.

The task is to sort an array in a wave form, where each element is greater than or equal to its adjacent elements.

• Iterate through the array and swap adjacent elements if they do not follow the wave pattern

• Start from the second element and compare it with the previous element, swap if necessary

• Continue this process until the end of the array

• Repeat the process for the remaining elements

• Return the sorted wave array

Find the K-th permutation sequence of numbers from 1 to N.

• Generate all permutations of numbers from 1 to N using backtracking or next_permutation function.

• Sort the permutations in lexicographical order.

• Return the K-th permutation from the sorted list.

This question asks to find the position of a target integer in a row-wise and column-wise sorted matrix.

• Iterate through each row and column of the matrix

• Compare the target integer with the current element

• If the target integer is found, return the position as {i, j}

• If the target integer is not found, return {-1, -1}

Calculate the number of ways Preeti can purchase items within budget, with at least one item quantity differing.

• Use dynamic programming to calculate the number of ways to purchase items within budget.

• Consider different scenarios where Preeti buys different quantities of each item.

• Return the result modulo 10^9 + 7 to handle large answers.

The problem involves finding the number of ways to tile a 2xN board using 2x1 tiles.

• Use dynamic programming to solve this problem efficiently.

• Define a recursive function to calculate the number of ways to tile the board.

• Consider both horizontal and vertical placements of tiles.

• Implement the function to handle large values of N using modulo arithmetic.

• Example: For N = 4, the number of ways to tile the board is 5.

Find the intersection of two square images represented as trees based on color rules.

• A white node (W) intersects with another white node (W) results in W.

• A black node (B) intersects with another black node (B) results in B.

• A white node (W) intersects with a black node (B) results in W.

• A mixed node (M) will have 4 children representing the intersection of its quadrants.

The task is to print the right view of a binary tree, representing nodes visible from the right side in top-to-bottom order.

• Traverse the tree level by level and keep track of the rightmost node at each level

• Print the rightmost node of each level to get the right view of the tree

• Use a queue for level order traversal and a map to store the rightmost nodes

Implement a cache with insert, update, and retrieve operations, returning results of retrieve operations in order.

• Create a cache data structure with specified size 'N'.

• Implement insert and update operations based on the given criteria.

• For retrieve operation, return the value associated with the 'U_ID' if present, else return -1.

• Handle cases where the cache is full and least frequently used items need to be removed.

• Return the results of all retrieve operations in the order the...read more

The task is to count the total number of '1' in the binary representation of all numbers from 1 to N.

• Convert each number from 1 to N into its binary representation

• Count the number of '1' bits in each binary representation

• Sum up the counts of '1' bits for all numbers

• Return the sum modulo 1e9+7

Validate IFSC code based on given rules and return True or False for each test case.

• Check if the code is 11 characters long.

• Verify the first four characters are uppercase alphabets.

• Ensure the fifth character is '0'.

• Validate that the last six characters are alphanumeric.

Calculate the earliest day on which Ninja can buy all candies with special offers.

• Iterate through each day and check if any special offer is available for candies Ninja wants to buy

• Keep track of the minimum day on which Ninja can buy all candies

• Consider both regular price and sale price of candies

Check if a string is formed by interleaving two other strings.

• Iterate through characters of A, B, and C simultaneously to check if C is formed by interleaving A and B.

• Use dynamic programming to efficiently solve the problem.

• Handle edge cases like empty strings or unequal lengths of A, B, and C.

• Example: A = 'aab', B = 'abc', C = 'aaabbc' should return True.