--description--

Given an array of numbers, return a new array containing the value needed to get from each number to the next number.

• For the last number, use 0 since there is no next number.

For example, given [1, 2, 4, 7], return [1, 2, 3, 0].

--hints--

findDifferences([1, 2, 4, 7]) should return [1, 2, 3, 0].

assert.deepEqual(findDifferences([1, 2, 4, 7]), [1, 2, 3, 0]);

findDifferences([10, 15, 19, 22, 24, 25]) should return [5, 4, 3, 2, 1, 0].

assert.deepEqual(findDifferences([10, 15, 19, 22, 24, 25]), [5, 4, 3, 2, 1, 0]);

findDifferences([25, 20, 16, 13, 11, 10]) should return [-5, -4, -3, -2, -1, 0].

assert.deepEqual(findDifferences([25, 20, 16, 13, 11, 10]), [-5, -4, -3, -2, -1, 0]);

findDifferences([0, 1, 2, 2, 3, 3, 4, 5]) should return [ 1, 1, 0, 1, 0, 1, 1, 0 ].

assert.deepEqual(findDifferences([0, 1, 2, 2, 3, 3, 4, 5]), [ 1, 1, 0, 1, 0, 1, 1, 0 ]);

findDifferences([1, 2, 5, 12, 34, -15, -1, 41, 113, -222, -99, -40, 10, -18, -6, -2, -1]) should return [1, 3, 7, 22, -49, 14, 42, 72, -335, 123, 59, 50, -28, 12, 4, 1, 0].

assert.deepEqual(findDifferences([1, 2, 5, 12, 34, -15, -1, 41, 113, -222, -99, -40, 10, -18, -6, -2, -1]), [1, 3, 7, 22, -49, 14, 42, 72, -335, 123, 59, 50, -28, 12, 4, 1, 0]);

--seed--

--seed-contents--

function findDifferences(arr) {

  return arr;
}

--solutions--

function findDifferences(arr) {
  const result = [];

  for (let i = 0; i < arr.length; i++) {
    result.push(arr[i + 1] - arr[i] || 0);
  }

  return result;
}