JavaScriptAlgorithms/Sorts/SelectionSort.js at master · manojsdeveloper/JavaScriptAlgorithms · GitHub

35 lines (34 loc) · 1.47 KB

/* The selection sort algorithm sorts an array by repeatedly finding the minimum element

*(considering ascending order) from unsorted part and putting it at the beginning. The

*algorithm maintains two subarrays in a given array.

*1) The subarray which is already sorted.

*2) Remaining subarray which is unsorted.

*In every iteration of selection sort, the minimum element (considering ascending order)

*from the unsorted subarray is picked and moved to the sorted subarray.

export const selectionSort = (list) => {

if (!Array.isArray(list)) {

throw new TypeError('Given input is not an array')

}

const items = [...list] // We don't want to modify the original array

const length = items.length

for (let i = 0; i < length - 1; i++) {

if (typeof items[i] !== 'number') {

throw new TypeError('One of the items in your array is not a number')

}

// Number of passes

let min = i // min holds the current minimum number position for each pass; i holds the Initial min number

for (let j = i + 1; j < length; j++) { // Note that j = i + 1 as we only need to go through unsorted array

if (items[j] < items[min]) { // Compare the numbers

min = j // Change the current min number position if a smaller num is found

}

if (min !== i) {

// After each pass, if the current min num != initial min num, exchange the position.

// Swap the numbers

[items[i], items[min]] = [items[min], items[i]]

}

return items

}

Expand file tree