540. Zigzag Iterator [LintCode]

Given two 1d vectors, implement an iterator to return their elements alternately.

Example

Given two 1d vectors:

v1 = [1, 2]
v2 = [3, 4, 5, 6]

By calling next repeatedly until hasNext returnsfalse, the order of elements returned by next should be:[1, 3, 2, 4, 5, 6].

public class ZigzagIterator {
    /**
     * @param v1 v2 two 1d vectors
     */
    public ZigzagIterator(List<Integer> v1, List<Integer> v2) {
        // initialize your data structure here.
    }

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

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

/**
 * Your ZigzagIterator object will be instantiated and called as such:
 * ZigzagIterator solution = new ZigzagIterator(v1, v2);
 * while (solution.hasNext()) result.add(solution.next());
 * Output result
 */