541. Zigzag Iterator II [LintCode]

Follow up Zigzag Iterator : What if you are given k1d vectors? How well can your code be extended to such cases? The "Zigzag" order is not clearly defined and is ambiguous fork > 2cases. If "Zigzag" does not look right to you, replace "Zigzag" with "Cyclic".

Example

Givenk = 31d vectors:

[1,2,3]
[4,5,6,7]
[8,9]

Return[1,4,8,2,5,9,3,6,7].

public class ZigzagIterator2 {
    /**
     * @param vecs a list of 1d vectors
     */
    public ZigzagIterator2(ArrayList<ArrayList<Integer>> vecs) {
        // initialize your data structure here.
    }

    public int next() {
        // Write your code here
    }

    public boolean hasNext() {
        // Write your code here   
    }
}

/**
 * Your ZigzagIterator2 object will be instantiated and called as such:
 * ZigzagIterator2 solution = new ZigzagIterator2(vecs);
 * while (solution.hasNext()) result.add(solution.next());
 * Output result
 */