ACM的水题。明明运行正确，但提交就是wrong answer呐，大佬求教

 #include <iostream>
using namespace std;
int main()
{
    int Lu[100];
    int n, x = 0;
    while (cin >> n && n < 100)
    {
        if (n == 0 || n < 0)
            break;

        for (int i = 0; i < n; i++)
            cin >> Lu[i];

        int key = Lu[0];

        for (int i = 0; i < n; i++)
        {
            while (Lu[i] <= Lu[x])
                ++x;
            if (x == n)
            {
                Lu[0] = Lu[i];
                Lu[i] = key;
                break;
            }
        }
        for (int i = 0; i < n; i++)
            cout << Lu[i] << ' ';
        cout << endl;
        x = 0;
    }
    return 0;
}