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class Solution {
public:
    void sortColors(vector<int>& nums) {
        int low = 0, mid = 0, high = nums.size() - 1;
        while (mid <= high) {
            if (nums[mid] == 0) {
                swap(nums[low], nums[mid]);
                low++;
                mid++;
            } else if (nums[mid] == 1) {
                mid++;
            } else {
                swap(nums[mid], nums[high]);
                high--;
            }
        }
    }
};

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class Solution {
public:
    void sortColors(vector<int>& nums) {
        int count[3] = {0, 0, 0};
        for (int num : nums) {
            count[num]++;
        }

        int index = 0;
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < count[i]; j++) {
                nums[index++] = i;
            }
        }
    }
};