Sort Colors

Given an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue.

• Time: O(n)
• Space: O(1)

public void sortColors(int[] nums) {
    int i = 0, l = 0, r = nums.length - 1;
    while (i <= r) {
        if (nums[i] == 0) {
            nums[i++] = nums[l];
            nums[l++] = 0;
        } else if (nums[i] == 2) {
            nums[i] = nums[r];
            nums[r--] = 2;
        } else {
            i++;
        }
    }
}