quickSort.js 961 B

1234567891011121314151617181920212223242526272829303132
  1. var swap = require('./swap');
  2. var isSorted = require('./isSorted');
  3. exports = function(arr) {
  4. var cmp =
  5. arguments.length > 1 && arguments[1] !== undefined
  6. ? arguments[1]
  7. : isSorted.defComparator;
  8. return quickSort(arr, 0, arr.length - 1, cmp);
  9. };
  10. function quickSort(arr, left, right, cmp) {
  11. if (arr.length <= 1) return arr;
  12. var idx = partition(arr, left, right, cmp);
  13. if (left < idx - 1) quickSort(arr, left, idx - 1, cmp);
  14. if (idx < right) quickSort(arr, idx, right, cmp);
  15. return arr;
  16. }
  17. function partition(arr, left, right, cmp) {
  18. var pivot = arr[floor((right + left) / 2)];
  19. while (left <= right) {
  20. while (cmp(arr[left], pivot) < 0) left++;
  21. while (cmp(arr[right], pivot) > 0) right--;
  22. if (left <= right) {
  23. swap(arr, left, right);
  24. left++;
  25. right--;
  26. }
  27. }
  28. return left;
  29. }
  30. var floor = Math.floor;
  31. module.exports = exports;