Software Testing Engineer

Step 1: I took the input from the user using the Scanner class to read an integer.
Step 2: I used the modulus operator % to check the remainder when the number is divided by 2.
Step 3: Printed the result accordingly using a simple if-else block.

Step 1: I initially thought of storing the three numbers in an array and sorting it using bubble sort to get the largest value at the end.
Step 2: Then I used the Math.max() method to find the maximum of two numbers, and then compared the result with the third number.
Step 3: Finally, I solved it using simple if-else conditions which are direct, readable, and optimal for 3 values.

Tip 1: Understand the usage of ORDER BY and LIMIT/OFFSET for fetching sorted values.
Tip 2: Learn how to use subqueries to compare each value with the max of the remaining.
Tip 3: Practice edge cases — what if there is no second highest? Use NULL handling or LIMIT with OFFSET.

Tip 1: Think about dividing the balls into 3 groups — this is key to solving most balance puzzles.
Tip 2: In puzzles with limited attempts, try to maximize the information gained from each step.
Tip 3: Remember, a balance scale doesn’t give numbers — it gives 3 possible outcomes: left side heavier, right side heavier, or equal.

Tip 1: Understand the basic concepts of Data Structures.
Tip 2: Practice writing code for common array problems like finding the largest, second largest, minimum, and sorting arrays.

Step 1: Initially, I tried solving the problem using sorting the array and then checking the missing element by iterating over it. But this approach increased the time complexity to O(N log N) due to sorting.

Step 2: The interviewer asked me to optimize the solution with a better approach without sorting.

Step 3: Then I applied the Mathematical Formula method:
Sum of first N numbers = N*(N+1)/2
→ Calculate the sum of all array elements.
→ Subtract the sum of array elements from total sum (N*(N+1)/2) to get the missing number.
The interviewer was happy with this optimized solution because it had O(N) time complexity and O(1) space complexity

Understand real-time examples of Semaphore like traffic signals, printer access, and critical section problems.