LeetCode "Zigzag Iterator"

class ZigzagIterator {
    int x;    
    int i;
    int max_x;
    vector<vector<int>*> l;
    
    void moveon()
    {
        int oldi= i;
        i = (i + 1) % l.size();
        x += i <= oldi;
    }
public:
    ZigzagIterator(vector<int>& v1, vector<int>& v2) 
    {
        i = x = 0;
        max_x = max(v1.size(), v2.size());

        if(v1.size() > 0)    l.push_back(&v1);
        if(v2.size() > 0)    l.push_back(&v2);
    }

    int next() 
    {
        int ret = (*l[i])[x];
        while(moveon(), x < max_x && l[i]->size() <= x);return ret;
　　　　 return ret;
    }

    bool hasNext() 
    {
        return x < max_x;
    }
};