README.md

Sophie's Maths

In Terminal, npx <url-of-this-gist>

IMPORTANT: If you have made any changes in the script, to make the changes visible, make sure you update the version number in package.json

index.js

#!/usr/bin/env node

function random(min, max, exclude) {
  let a;
  do {
    a = Math.floor(Math.random() * (max - min + 1) + min);
  } while (a === exclude);
  return a;
}

function duplicated(a, e, exchangeable) {
  const same = a.find(element => {
    if (element[0] === e[0] && element[1] === e[1]) {
      return true;
    }
    if (exchangeable && element[0] === e[1] && element[1] === e[0]) {
      return true;
    }
    return false;
  });
  return !!same;
}

function addition() {
  const challenge = [];
  do {
    const e = [random(1, 20), 9];
    if (!duplicated(challenge, e, true)) {
      challenge.push(e);
    }
  } while (challenge.length < 12);
  challenge.map(e => {
    console.log(`${e[0]} + ${e[1]} =`);
  });
}

function subtraction() {
  const challenge = [];
  do {
    let a;
    let b;
    do {
      a = random(10, 20);
      b = 9;
    } while (a <= b);
    const e = [a, b];
    if (!duplicated(challenge, e, false)) {
      challenge.push(e);
    }
  } while (challenge.length < 11);
  challenge.map(e => {
    console.log(`${e[0]} - ${e[1]} =`);
  });
}

console.log('');
addition();
console.log('');
subtraction();

package.json

{
  "name": "maths-for-fattie-eggie",
  "version": "1.0.2",
  "bin": "./index.js"
}