A Common-Sense Guide to Data Structures and Algorithms in JavaScript, Volume 1

Exercises

The following exercises provide you with the opportunity to practice with optimizing for best- and worst-case scenarios. The solutions to these exercises are found in the section ​Chapter 6​.

1. Use Big O notation to describe the efficiency of an algorithm that takes 3N² + 2N + 1 steps.

2. Use Big O notation to describe the efficiency of an algorithm that takes N + log N steps.

3. The following function checks whether an array of numbers contains a pair of two numbers that add up to 10.

   function twoSum(array) {
     for (const [indexI, i] of array.entries()) {
       for (const [indexJ, j] of array.entries()) {
         if ((indexI !== indexJ) && (i + j === 10)) {
           return true;
         }
       }
     }
   
     return false;
   }

   What are the best-, ...