diff --git a/Sorts/SwapSort.js b/Sorts/SwapSort.js new file mode 100644 index 0000000000..65199d2ffa --- /dev/null +++ b/Sorts/SwapSort.js @@ -0,0 +1,31 @@ +/** + * @function SwapSort + * @description Swap Sort is an algorithm to find the number of swaps required to sort an array. + Time complexity of Swap Sort Algorithm is O(nlogn). + Auxiliary Space required for Swap Sort Algorithm is O(n). + * @param {Integer[]} items - Array of integers + * @return {Integer} - Number of swaps required to sort the array. + * @see [SwapSort](https://www.geeksforgeeks.org/minimum-number-swaps-required-sort-array/) + */ + +export function minSwapsToSort (items) { + const sortedArray = items.slice() + sortedArray.sort() + const indexMap = {} + for (let i = 0; i < items.length; i++) { + indexMap[items[i]] = i + } + let swaps = 0 + for (let i = 0; i < items.length; i++) { + if (items[i] !== sortedArray[i]) { + const temp = items[i] + items[i] = items[indexMap[sortedArray[i]]] + items[indexMap[sortedArray[i]]] = temp + + indexMap[temp] = indexMap[sortedArray[i]] + indexMap[sortedArray[i]] = i + swaps++ + } + } + return swaps +} diff --git a/Sorts/test/SwapSort.test.js b/Sorts/test/SwapSort.test.js new file mode 100644 index 0000000000..3a5d4f1d5a --- /dev/null +++ b/Sorts/test/SwapSort.test.js @@ -0,0 +1,18 @@ +import { minSwapsToSort } from '../SwapSort' + +describe('SwapSort', () => { + it('should work for empty arrays', () => { + expect(minSwapsToSort([])).toEqual(0) + }) + + it('should work for sorted arrays', () => { + expect(minSwapsToSort([1, 2, 3, 4, 5, 6])).toEqual(0) + }) + + it('should return correct results', () => { + expect(minSwapsToSort([7, 6, 2, 5, 11, 0])).toEqual(2) + expect(minSwapsToSort([3, 3, 2, 1, 0])).toEqual(2) + expect(minSwapsToSort([3, 0, 2, 1, 9, 8, 7, 6])).toEqual(4) + expect(minSwapsToSort([1, 0, 14, 0, 8, 6, 8])).toEqual(3) + }) +})