Coding interview problems

Last modified: April 5, 2023

Two Sum

Free. No login required. Python technical interview question: Two Sum

Merge Intervals

Given a collection of intervals, merge any overlapping intervals.

Reverse a String

reverse a string interview question

Longest Common Prefix

Find the longest common prefix string amongst an array of strings.

Palindrome String

Palindrome String: Free. No login required. Python technical interview question

Roman to Integer

Given a Roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999.

Letter Combinations of a Phone Number

Write a function to generate all possible combinations of letters that can be formed from a given string of digits representing a phone number.

Valid Parentheses

valid parentheses coding question

Find the Index of the First Occurrence in a String

Learn how to find the index of the first occurrence of a substring in a string in this coding interview problem.

Length of Last Word

Find the length of the last word in a given string.

Spiral Matrix

given number n return matrix n by n with numbers in spiral order