https://leetcode-cn.com/problems/sort-colors/

荷兰国旗的划分

  1. public void sortColors(int[] nums) {
  2.     int L = -1;
  3.     int R = nums.length;
  4.     int index = 0;
  5.     while (index < R) {
  6.         if (nums[index] == 0) {
  7.             swap(nums, ++L, index++);
  8.         } else if (nums[index] == 2){
  9.             swap(nums, --R, index);
  10.         } else { // 1
  11.             index++;
  12.         }
  13.     }
  14. }
  16. public void swap(int[] arr, int i, int j) {
  17.     int tmp = arr[i];
  18.     arr[i] = arr[j];
  19.     arr[j] = tmp;
  20. }