魔术索引II

class MagicIndex {
public:
    bool findMagicIndex(vector<int> A, int n) {
        // write code here
           if(A.size() == 0)
            return true;
        
        int i;
        for(i = 0; i < n; i++){
            if(A[i] == i)
                return true;
            else {
                if(A[i] < i)
                    i++;
                else
                    i = A[i];
            }
        }
        
        return false;
    }
};