keepOrder.md

Keep the Order

Task

• Your job here is to write a function (keepOrder in JS/CoffeeScript, keep_order in Ruby/Crystal/Python, keeporder in Julia), which takes a sorted array ary and a value val, and returns the lowest index where you could insert val to maintain the sorted-ness of the array. The input array will always be sorted in ascending order. It may contain duplicates.

• Do not modify the input.

Example

keepOrder([1, 2, 3, 4, 7], 5) //=> 4
                      ^(index 4)
keepOrder([1, 2, 3, 4, 7], 0) //=> 0
          ^(index 0)
keepOrder([1, 1, 2, 2, 2], 2) //=> 2
                ^(index 2)

Solution 1:

function keepOrder(ary, val) {
  return ary.filter((x) => x < val).length;
}

console.log(keepOrder([1, 2, 3, 4], 2)); // 1
console.log(keepOrder([1, 2, 3, 4], -1)); // 0

Solution 2:

function keepOrder(ary, val) {
  for (let i = 0; i < ary.length; i++) {
    if (val <= ary[i]) return i;
  }
  return ary.length;
}

console.log(keepOrder([1, 2, 3, 4, 7], 5)); // 4
console.log(keepOrder([1, 1, 2, 2, 2], 2)); // 2