CodeWars_Training/JavaScript/8_kyu/String_array_comparison/Formula.js at main · LucaArisci/CodeWars_Training · GitHub

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/* ----------------------------------------------------------------------------------------

    Now we will confect a reagent. There are eight materials to choose from, numbered
    1,2,..., 8 respectively.

    We know the rules of confect:

    material1 and material2 cannot be selected at the same time
    material3 and material4 cannot be selected at the same time
    material5 and material6 must be selected at the same time
    material7 or  material8 must be selected(at least one, or both)

    Task

    You are given a integer array formula. Array contains only digits 1-8 that
    represents material 1-8. Your task is to determine if the formula is valid.
    Returns true if it's valid, false otherwise.

    Example

    For formula = [1,3,7], The output should be true.

    For formula = [7,1,2,3], The output should be false.

    For formula = [1,3,5,7], The output should be false.

    For formula = [1,5,6,7,3], The output should be true.

    For formula = [6,7,8], The output should be false.

    For formula = [7,8], The output should be true.

    Note

    All inputs are valid. Array contains at least 1 digit. Each digit appears at most
    once.

---------------------------------------------------------------------------------------- */

/*
    Array.prototype.includes(): determines whether an array includes a certain value
                                among its entries, returning true or false as appropriate
*/

function isValid(formula) {
  if (formula.includes(1) && formula.includes(2)) {
    return false;
  } else if (formula.includes(3) && formula.includes(4)) {
    return false;
  } else if (formula.includes(5) && !formula.includes(6)) {
    return false;
  } else if (!formula.includes(5) && formula.includes(6)) {
    return false;
  } else if (!formula.includes(7) && !formula.includes(8)) {
    return false;
  } else {
    return true;
  }
}

/*
    Alternative solution:

    Array.prototype.includes(): determines whether an array includes a certain value
                                among its entries, returning true or false as appropriate
*/

function isValid(formula) {
  return (
    !(formula.includes(1) && formula.includes(2)) &&
    !(formula.includes(3) && formula.includes(4)) &&
    formula.includes(5) === formula.includes(6) &&
    (formula.includes(7) || formula.includes(8))
  );
}