75. Sort Colors

class Solution {
    public void sortColors(int[] nums) {
        if(nums == null || nums.length == 0) return;
        int count0 = 0;
        int count1 = 0;
        int count2 = 0;
        for(int i = 0; i < nums.length; i++) {
            if(nums[i] == 0) {
                count0++;
            }else if(nums[i] == 1) {
                count1++;
            }else {
                count2++;
            }
        }
        int i = 0;
        for(i = 0; i < count0; i++) {
            nums[i] = 0;
        }
        for(i = count0; i < count0 + count1; i++) {
            nums[i] = 1;
        }
        for( ; i < nums.length; i++) {
            nums[i] = 2;
        }
        
    }
}