Week 6: Intro to Algorithms

Week	Topic	Learning Objectives	Key Resources
6	Intro to Algorithms	Students will be able to define an algorithm, identify properties of a good algorithm, and understand methods of solving algorithms.	Week 6 Slides

Overview

• Intro to algorithms
  • Solving problems using algorithms
  • Use of algorithms
    • Web development
    • Mathematics
    • Operations Research
    • Artificial intelligence
    • Data science
• Pseudocode
• Intro to IDEs (CTD recommends VS Code)

Guidance for Mentors

Some potential trouble spots for students:

1. Understanding the relevance
2. Finding the patience for the most elegant/efficient solution to a problem rather than a brute force approach.
3. Connecting theory to practice

The assignment questions have not necessarily been covered in depth in the lessons so far, students are encouraged to use additional resources and research to help.

Assignment Rubric

Question 1:

function pairsMaker(array) {

  // remove duplicate numbers
  let uniqueElements = new Set(array);
  let tempArray = [...uniqueElements];

  // Now, create the pairs
  let pairs = [];
  for (let i = 0; i < tempArray.length; i++) {
    for (let j = 0; j < tempArray.length; j++) {
      pairs.push([tempArray[i], tempArray[j]]);
    }
  }
  return pairs;
}

let numbersArray = [1, 2, 1, 1, 3, 5, 2];

console.log(
  `Q1 pairsMaker: input: [${numbersArray}], output:`,
  pairsMaker(numbersArray),
);

Question 2:

function twoSum(arr, target) {
  let complements = new Set();

  for (let i = 0; i < arr.length; i++) {
    let complement = target - arr[i];
    if (complements.has(complement)) {
      return true;
    }
    complements.add(arr[i]);
  }

  return false;
 }

let numbers = [2, 4, 6, 8, 10];
let target = 12;

console.log("Q2: ", target + ": ", twoSum(numbers, target));

Question 3:

function pairProduct(arr, product) {
  let complements = new Set();

  for (let i = 0; i < arr.length; i++) {
    if (product % arr[i] === 0) {
      let complement = product / arr[i];
      if (complements.has(complement)) {
        return true;
      }
      complements.add(arr[i]);
    }
  }

  return false;
}

let numbers3 = [2, 4, 6, 8, 10];
let targetProduct = 20;

console.log("Q3: ", targetProduct + ": ", pairProduct(numbers3, targetProduct));

Question 4:

function strangeSums(arr) {
  let count = 0;
  let complements = new Set();

  for (let i = 0; i < arr.length; i++) {
    let complement = -arr[i];
    if (complements.has(complement)) {
      count++;
    }
    complements.add(arr[i]);
  }

  return count;
}

let numbers4 = [2, -2, 3, -3, 4, -4, 5, -5];
console.log("Q4: ", strangeSums(numbers4));