weekly_programming_challenges.js

//20-10-2020
//Where do i belong

const getIndex = (arr, num) => {
  if (!Array.isArray(arr) || !arr.length || !Number.isFinite(num)) {
    return null;
  }
  arr.push(num);
  const newArr = arr.sort();
  const position = newArr.indexOf(num);
  return position;
};
console.log(getIndex([5, 2, 3, 1, 0], 4));

//Tutorial Method

const getIndexOfNum = (arr, num) => {
  arr.sort((a, b) => {
    return a - b;
  });
  for (let i = 0; i < arr.length; i++) {
    if (num <= arr[i]) {
      return i;
    }
  }
  return arr.length;
};
console.log(getIndexOfNum([22, 48, 62, 90, 12, 30], 50));

//21/10/2020
//Caesars Cipher

const caesarCipher = str => {
  if (typeof str !== "string" || !str.length) {
    return null;
  }
  let char = "";
  for (let i = 0; i < str.length; i++) {
    let asciiCode = str[i].charCodeAt();
    if (asciiCode >= 65 && asciiCode <= 77) {
      char = char + String.fromCharCode(asciiCode + 13);
    } else if (asciiCode >= 78 && asciiCode <= 90) {
      char = char + String.fromCharCode(asciiCode - 13);
    } else {
      char = char + str[i];
    }
  }
  return char;
};

//tests

console.log(caesarCipher("ABCD EFGH IJKL MNOP") === "NOPQ RSTU VWXY ZABC");

//22/20/2020
//sum all numbers in a range
//we ll pass you an array of two numbers and all numbers between them
//the lowest no ll always not come first

const sumAll = arr => {
  if (!Array.isArray(arr) || !arr.length) {
    return null;
  }
  let sum = 0;
  if (arr[0] < arr[arr.length - 1]) {
    for (let i = arr[arr.length - 1]; i >= arr[0]; i--) {
      sum = sum + i;
    }
  } else {
    for (let i = arr[arr.length - 1]; i <= arr[0]; i++) {
      sum = sum + i;
    }
  }
  return sum;
};

console.log(sumAll([4, 1]));

//tutorial

const sumItUp = arr => {
  let sum = 0;
  let start = Math.min(arr[0], arr[1]);
  let end = Math.max(arr[0], arr[1]);
  for (let i = start; i <= end; i++) {
    sum = sum + i;
  }
  return sum;
};
console.log(sumItUp([2, 4]));
//23/10/2020
//Diff two arrays
//You are given two arrays, you have to return all the unique numbers

const uniqueNum = (arr1, arr2) => {
  if (
    !Array.isArray(arr1) ||
    !Array.isArray(arr2) ||
    !arr1.length ||
    !arr2.length
  ) {
    return null;
  }
  const uniques = [];

  for (let i = 0; i < arr1.length; i++) {
    if (arr2.indexOf(arr1[i]) === -1) {
      uniques.push(arr1[i]);
    }
  }
  for (let j = 0; j < arr2.length; j++) {
    if (arr1.indexOf(arr2[j]) === -1) {
      uniques.push(arr2[j]);
    }
  }
  return uniques;
};

console.log(uniqueNum([1, 2, 3, 4], [1, 4, 5, 6, 7, 8, 2]));

//Using filter method

const uniNum = (arr1, arr2) => {
  const arr = [...arr1, ...arr2];
  return arr.filter(num => {
    console.log(num, "num");
    if (arr1.indexOf(num) === -1 || arr2.indexOf(num) === -1) {
      return num;
    }
  });
};

console.log(uniNum([1, 2, 3], [1, 2, 3, 4]));