@vanillaes/computer-science/src/Sort/SelectionSort.js

Algorithms and Data Structures implemented in modern JS

/**
 * A SelectionSort algorithm
 *
 * The sort works by iterating through the array starting from the beginning.
 * Each item is compared to every subsequent item in the array to determine
 * which is smaller. Either the current item is kept or a smaller item is
 * swapped into its spot. This repeats until the order of items is arranged
 * from smallest-to-largest.
 *
 * @export
 * @param {*[]} array the input array
 * @param {Function} [comparator] a function to compare 2 values (defaults asc->desc)
 * @param {Function} [step] an optional function that gets applied at each step
 * @returns {*[]} the sorted array
 */
function SelectionSort (array, comparator = (a, b) => a < b, step) {
  const N = array.length
  for (let i = 0; i < N; i++) {
    let min = i
    for (let j = i + 1; j < N; j++) {
      if (comparator(array[j], array[min])) {
        min = j
      }
    }
    if (i !== min) {
      [array[i], array[min]] = [array[min], array[i]]
    }
    if (step) { step(array) }
  }

  return array
}

export { SelectionSort }