/* Wikipedia says: Cycle sort is an in-place, unstable sorting algorithm, a comparison sort that is theoretically optimal in terms of the total number of writes to the original array, unlike any other in-place sorting algorithm. It is based on the idea that the permutation to be sorted can be factored into cycles, which can individually be rotated to give a sorted result. */ function cycleSort (list) { let writes = 0 for (let cycleStart = 0; cycleStart < list.length; cycleStart++) { let value = list[cycleStart] let position = cycleStart // search position for (let i = cycleStart + 1; i < list.length; i++) { if (list[i] < value) { position++ } } // if its the same continue if (position === cycleStart) { continue } while (value === list[position]) { position++ } const oldValue = list[position] list[position] = value value = oldValue writes++ // rotate the rest while (position !== cycleStart) { position = cycleStart for (let i = cycleStart + 1; i < list.length; i++) { if (list[i] < value) { position++ } } while (value === list[position]) { position++ } const oldValueCycle = list[position] list[position] = value value = oldValueCycle writes++ } } return writes } const arrOrignal = [5, 6, 7, 8, 1, 2, 12, 14] // Array before Sort console.log(arrOrignal) cycleSort(arrOrignal) // Array after sort console.log(arrOrignal)