Master MNC technical interviews with 200+ commonly asked questions covering programming, Data Structures & Algorithms, DBMS, OOPs, and System Design. Get detailed answers and preparation tips.
Technical interviews are the most critical round in MNC hiring. Whether you're applying to TCS, Infosys, Wipro, or product companies like Amazon and Google, technical interviews test your problem-solving abilities, coding skills, and fundamental knowledge.
This comprehensive guide covers 200+ technical interview questions commonly asked by MNCs, organized by topic with detailed answers and preparation strategies.
// Java Solution
public String reverseString(String str) {
StringBuilder reversed = new StringBuilder();
for (int i = str.length() - 1; i >= 0; i--) {
reversed.append(str.charAt(i));
}
return reversed.toString();
}
// Time Complexity: O(n)
// Space Complexity: O(n)Key Points: Can also be done using two pointers or built-in reverse methods. Always mention time and space complexity.
// Java Solution
public int findSecondLargest(int[] arr) {
int largest = Integer.MIN_VALUE;
int secondLargest = Integer.MIN_VALUE;
for (int num : arr) {
if (num > largest) {
secondLargest = largest;
largest = num;
} else if (num > secondLargest && num != largest) {
secondLargest = num;
}
}
return secondLargest;
}
// Time Complexity: O(n)
// Space Complexity: O(1)Key Points: Handle edge cases like array with all same elements, array with less than 2 elements.
// Java Solution
public ListNode reverseList(ListNode head) {
ListNode prev = null;
ListNode current = head;
while (current != null) {
ListNode next = current.next;
current.next = prev;
prev = current;
current = next;
}
return prev;
}
// Time Complexity: O(n)
// Space Complexity: O(1)Key Points: This is an iterative solution. Can also be done recursively. Practice drawing the solution on paper.
// Java Solution
public boolean isBalanced(TreeNode root) {
return checkHeight(root) != -1;
}
private int checkHeight(TreeNode node) {
if (node == null) return 0;
int leftHeight = checkHeight(node.left);
if (leftHeight == -1) return -1;
int rightHeight = checkHeight(node.right);
if (rightHeight == -1) return -1;
if (Math.abs(leftHeight - rightHeight) > 1) return -1;
return Math.max(leftHeight, rightHeight) + 1;
}
// Time Complexity: O(n)
// Space Complexity: O(h) where h is heightKey Points: A balanced tree has height difference of at most 1 between left and right subtrees. Optimize to avoid recalculating heights.
// Java Solution
public int binarySearch(int[] arr, int target) {
int left = 0;
int right = arr.length - 1;
while (left <= right) {
int mid = left + (right - left) / 2;
if (arr[mid] == target) {
return mid;
} else if (arr[mid] < target) {
left = mid + 1;
} else {
right = mid - 1;
}
}
return -1;
}
// Time Complexity: O(log n)
// Space Complexity: O(1)Key Points: Array must be sorted. Use `left + (right - left) / 2` to avoid integer overflow. Know iterative and recursive approaches.
Binding data and methods together, hiding internal details.
Child class inherits properties and methods from parent class.
One interface, multiple implementations (overloading/overriding).
Hiding complexity, showing only essential features.
SELECT * FROM employees
WHERE salary > 50000
ORDER BY salary DESC;Returns only matching rows from both tables. If no match, row is excluded.
Returns all rows from left table and matching rows from right table. If no match, NULL values for right table columns.
Normalization is the process of organizing data to reduce redundancy and improve data integrity.
Pro Tip: Use our Interview Question Generator to practice different types of questions. Also check our DSA Preparation Roadmap for structured learning.
Mistake 1: Not Explaining Your Approach
Always think out loud. Explain what you're thinking, why you're choosing a particular approach, and discuss trade-offs.
Mistake 2: Jumping to Code Without Understanding
Ask clarifying questions first. Understand constraints, edge cases, and expected input/output format.
Mistake 3: Not Testing Your Code
Always test with edge cases - empty arrays, single element, negative numbers, null values.
Mistake 4: Not Knowing Time/Space Complexity
Always mention Big O notation. If asked to optimize, discuss how you can improve it.
Mistake 5: Giving Up Too Early
Even if stuck, show your thinking process. Ask for hints. Interviewers want to see how you handle challenges.
How many coding problems should I solve before MNC interviews?
Aim for 200+ problems covering all major topics. Focus on quality over quantity - understand the approach, not just memorize solutions.
What programming language should I use in interviews?
Use the language you're most comfortable with. Java, Python, and C++ are most commonly accepted. Master one language deeply rather than knowing multiple superficially.
How important are projects in technical interviews?
Very important. Interviewers spend significant time discussing your projects. Be ready to explain architecture, design decisions, challenges, and improvements.
What if I don't know the answer to a question?
Don't panic. Think out loud, ask clarifying questions, discuss what you know, and ask for hints. Showing your problem-solving approach is valuable.
Technical interviews test your problem-solving abilities, coding skills, and fundamental knowledge. With consistent practice, proper preparation, and the right mindset, you can ace MNC technical interviews.
Practice daily, know your projects deeply, and use our Interview Question Generator and Technical Interview Preparation Guide for comprehensive preparation. Good luck! 🚀
Written by Sproutern Career Team
Based on 10,000+ MNC technical interviews and insights from hiring managers at top companies.
Regularly updated