10+ TCS Interview Questions and Answers

Find the minimum time required to rot all fresh oranges in a grid.

• Use Breadth First Search (BFS) to simulate the rotting process.

• Track the time taken to rot all oranges and return the result.

• Handle edge cases like no fresh oranges or unreachable fresh oranges.

• Consider using a queue to efficiently process adjacent oranges.

The task is to find the first petrol pump from which a truck can complete a full circle or determine if it's impossible.

• Iterate through each petrol pump and calculate the remaining petrol after reaching the next pump.

• If the remaining petrol is negative at any point, reset the starting pump to the next pump and continue.

• If the total remaining petrol is non-negative after completing the circle, return the index of the starting pump.

• If the total remaining petrol is negative afte...read more

Design a special stack that supports constant time operations like push, pop, top, and getMin.

• Use two stacks - one to store the elements and another to store the minimum values encountered so far

• When pushing, check if the element is smaller than the current minimum and update the minimum stack accordingly

• For pop, top, and getMin operations, simply access the top elements of the respective stacks

• Ensure to handle cases where the stack is empty

The problem involves finding the total number of unique paths from the top-left corner to the bottom-right corner of an M x N matrix with allowed moves only to the right or down.

• Use dynamic programming to solve the problem efficiently.

• Create a 2D array to store the number of unique paths for each cell in the matrix.

• Initialize the first row and first column with 1 as there is only one way to reach each cell in the first row and column.

• For each cell (i, j), the number of unique...read more

Rotate a linked list by K positions in a clockwise direction.

• Traverse the linked list to find the length and the last node.

• Connect the last node to the head to form a circular linked list.

• Find the new head by moving (length - K) steps from the original head.

• Break the circular list at the new head to get the rotated linked list.

Check if the binary representation of a given integer is a palindrome.

• Convert the integer to binary representation.

• Check if the binary representation is a palindrome by comparing it with its reverse.

• Return true if it is a palindrome, false otherwise.

Print Fibonacci series

• Start with 0 and 1 as the first two numbers

• Add the previous two numbers to get the next number in the series

• Repeat until desired number of terms is reached

Rolling hash is a hashing technique used in data structures and algorithms to efficiently compare substrings of text.

• Rolling hash is used in algorithms like Rabin-Karp string matching algorithm.

• It involves updating the hash value of a substring by removing the contribution of the first character and adding the contribution of the next character.

• It is useful for comparing substrings in constant time complexity.

Multi threading in Java allows multiple threads to execute concurrently, improving performance and responsiveness.

• Multi threading is achieved in Java by extending the Thread class or implementing the Runnable interface.

• Threads share the same memory space, allowing them to communicate and synchronize using methods like wait(), notify(), and notifyAll().

• Concurrency issues like race conditions and deadlocks can occur in multi-threaded applications and must be carefully managed.

• E...read more