tech-interview-handbook/algorithms/math.md

id	title
math	Math

• Create a square root function.
• Given a string such as "123" or "67", write a function to output the number represented by the string without using casting.
• Make a program that can print out the text form of numbers from 1 - 1000 (ex. 20 is "twenty", 105 is "one hundred and five").
• Write a function that parses Roman numerals.
  • E.g. XIV returns 14.
• Write in words for a given digit.
  • E.g. 123 returns one hundred and twenty three.
• Given a number N, find the largest number just smaller than N that can be formed using the same digits as N.
• Compute the square root of N without using any existing functions.
• Given numbers represented as binary strings, and return the string containing their sum.
  • E.g. add('10010', '101') returns '10111'.
• Take in an integer and return its english word-format.
  • E.g. 1 -> "one", -10,203 -> "negative ten thousand two hundred and three".
• Write a function that returns values randomly, according to their weight. Suppose we have 3 elements with their weights: A (1), B (1) and C (2). The function should return A with probability 25%, B with 25% and C with 50% based on the weights.
  • Source
• Given a number, how can you get the next greater number with the same set of digits?
  • Source