LeetCode - Refresh - Sort Colors

class Solution {
public:
    void sortColors(int A[], int n) {
        auto swap = [](int &a, int &b){int t = a; a = b; b = t;};
        int start = 0, end = n-1, runner = 0;
        while (runner <= end) {
            if (A[runner] == 0) {
                swap(A[runner++], A[start++]);
                continue;
            }
            if (A[runner] == 2) {
                swap(A[runner], A[end--]);
                continue;
            }
            runner++;
        }
    }
};