DSA interview questions
Review short answers, detailed answers, practical code and common mistakes.
1. How would you explain DSA Introduction in DSA during an interview?beginner
DSA Introduction is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem dsa introduction solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}2. How would you explain Problem Solving Method in DSA during an interview?beginner
Problem Solving Method is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem problem solving method solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
3. How would you explain Time Complexity in DSA during an interview?beginner
Time Complexity is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem time complexity solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
4. How would you explain Space Complexity in DSA during an interview?beginner
Space Complexity is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem space complexity solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}5. How would you explain Big O Tradeoffs in DSA during an interview?beginner
Big O Tradeoffs is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem big o tradeoffs solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
6. How would you explain Arrays in DSA during an interview?beginner
Arrays is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem arrays solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
7. How would you explain Strings in DSA during an interview?beginner
Strings is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem strings solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}8. How would you explain Objects and Hash Maps in DSA during an interview?beginner
Objects and Hash Maps is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem objects and hash maps solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
9. How would you explain Sets and Frequency Counting in DSA during an interview?beginner
Sets and Frequency Counting is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem sets and frequency counting solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
10. How would you explain Prefix Sum in DSA during an interview?beginner
Prefix Sum is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem prefix sum solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}11. How would you explain Recursion in DSA during an interview?intermediate
Recursion is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem recursion solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
12. How would you explain Sorting in DSA during an interview?intermediate
Sorting is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem sorting solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
13. How would you explain Searching in DSA during an interview?intermediate
Searching is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem searching solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}14. How would you explain Binary Search in DSA during an interview?intermediate
Binary Search is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem binary search solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
15. How would you explain Stack in DSA during an interview?intermediate
Stack is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem stack solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
16. How would you explain Monotonic Stack in DSA during an interview?intermediate
Monotonic Stack is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem monotonic stack solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}17. How would you explain Queue in DSA during an interview?intermediate
Queue is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem queue solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
18. How would you explain Deque in DSA during an interview?intermediate
Deque is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem deque solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
19. How would you explain Linked List in DSA during an interview?intermediate
Linked List is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem linked list solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}20. How would you explain Hash Map in DSA during an interview?intermediate
Hash Map is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem hash map solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
21. How would you explain Heap and Priority Queue in DSA during an interview?advanced
Heap and Priority Queue is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem heap and priority queue solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
22. How would you explain Trees in DSA during an interview?advanced
Trees is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem trees solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}23. How would you explain Binary Tree Traversal in DSA during an interview?advanced
Binary Tree Traversal is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem binary tree traversal solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
24. How would you explain Binary Search Tree in DSA during an interview?advanced
Binary Search Tree is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem binary search tree solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
25. How would you explain Trie Basics in DSA during an interview?advanced
Trie Basics is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem trie basics solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}26. How would you explain Graphs in DSA during an interview?advanced
Graphs is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem graphs solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
27. How would you explain Graph BFS in DSA during an interview?advanced
Graph BFS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem graph bfs solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
28. How would you explain Graph DFS in DSA during an interview?advanced
Graph DFS is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem graph dfs solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
function uniqueValues(values) {
const seen = new Set();
return values.filter((value) => {
if (seen.has(value)) return false;
seen.add(value);
return true;
});
}29. How would you explain Shortest Path Basics in DSA during an interview?advanced
Shortest Path Basics is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem shortest path basics solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.
30. How would you explain Topological Sort in DSA during an interview?advanced
Topological Sort is best explained with its purpose, a small example, and one common mistake.
Start by naming the problem topological sort solves in DSA. Then show a short example, discuss the tradeoff, and mention how you would test it in a real codebase.