Klarna Coding Interview Questions
25 Klarna coding interview problems with full optimal solutions — 11 easy, 11 medium, 3 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an Klarna interviewer values, and a FAQ section.
Showing 11 problems of 25
- #1easyfoundational
1. Two Sum
Given an array of integers and a target, return indices of the two numbers that sum to the target.
- #2easyfoundational
2. Valid Parentheses
Determine if a string of brackets is balanced and properly nested.
- #3easyfoundational
3. Merge Two Sorted Lists
Merge two sorted linked lists into one sorted list by splicing nodes.
- #4easyfoundational
4. Remove Duplicates from Sorted Array
Remove duplicates from a sorted array in place and return the new length.
- #5easyfoundational
5. Remove Element
Remove all occurrences of a value in an array in place and return the new length.
- #6easyfoundational
6. Climbing Stairs
Count distinct ways to climb a staircase taking 1 or 2 steps at a time.
- #7easyfoundational
7. Best Time to Buy and Sell Stock
Find the maximum profit from a single buy-sell pair over a price series.
- #8easyfoundational
8. Contains Duplicate
Detect whether an array contains any duplicate value.
- #9easyfoundational
9. Single Number
Find the one element that appears exactly once in an array where every other element appears twice.
- #10easyfoundational
10. Missing Number
Find the single missing number from an array containing 0..n.
- #11easyfoundational
11. Reverse Linked List
Reverse a singly linked list in place.