TCS Interview Questions and Answers

Sort an array of 0s, 1s, and 2s in O(n) time complexity.

• Use three pointers to keep track of the positions of 0s, 1s, and 2s.

• Traverse the array and swap elements to their respective positions.

• The first pointer should point to the first occurrence of 1, and the second pointer should point to the first occurrence of 2.

• Example: [0, 1, 2, 0, 1, 2] -> [0, 0, 1, 1, 2, 2]

Sort an array of 0s, 1s, and 2s in O(n) time complexity.

• Use three pointers to keep track of the positions of 0s, 1s, and 2s.

• Traverse the array and swap elements to their respective positions.

• Time complexity is O(n) and space complexity is O(1).

Reverse a string while preserving the positions of special characters and spaces.

• Iterate through the string from both ends using two pointers

• Swap characters if both are alphabets or both are special characters

• Continue until the pointers meet in the middle

A program to determine if given strings are an anagram.

• Convert each string to lowercase and remove any non-alphabetic characters.

• Sort the characters in each string.

• Compare the sorted strings to check if they are equal.

Design a service to shorten long URLs into short ones.

• Generate a unique ID for each long URL and store it in a database.

• Map the unique ID to the long URL and store it in the database.

• Create a short URL by using the unique ID as a parameter.

• Redirect the short URL to the long URL when accessed.

• Implement security measures to prevent abuse and ensure privacy.

• Consider implementing analytics to track usage and performance.