linearSearch<E> function

int linearSearch<E>(
  1. List<E> list,
  2. E value, {
  3. int? start,
  4. int? count,
})

Returns the first index of the value in the list, otherwise -1.

You can control the range to search using the start and count parameters.

  • If start is given, search start there and go towards the end of the list.
  • If start is not below the length of the list, -1 will be returned.
  • If start is negative, search starts at start + count or 0, whichever is greater.
  • If the count parameter is given, it will check up to count numbers of items.
  • If count is negative, -1 will be returned.

Complexity: Time O(n) | Space O(1)

Implementation

int linearSearch<E>(
  List<E> list,
  E value, {
  int? start,
  int? count,
}) {
  int l, h;
  int n = list.length;

  // determine range [l, h)
  l = start ?? 0;
  h = n;
  if (count != null) {
    if (count < 0) return -1;
    h = l + count;
    if (h > n) h = n;
  }
  if (l < 0) l = 0;

  // forward loop in range [l, h)
  for (; l < h; ++l) {
    if (list[l] == value) {
      return l;
    }
  }

  return -1;
}